Welcome to spring on the stream! As per usual, I'm including as many movies as I can per each category as I scour Netflix, Hulu, Amazon Prime, Criterion Channel, HBO Max, Peacock, Fandor, Shudder, Arrow Video, Tubi, Midnight Pulp (a "+" will be included wherever subscription fees apply), VUDU’s free selections, The Roku Channel, Popcorn Flix, Crackle, Dark Matter TV, Night Flight, Shout Factory TV (though most of their titles can also be watched via Amazon Prime).
Due to flimsy copyright, many free services, including YouTube, have loads of spaghetti westerns to choose from. So, for this entry, I’m also adding one more free-with-ads app, Spaghetti Westerns Draw, which overlaps with other grey market/budget apps/streaming sites, as well as Amazon Prime. Again, be warned – all of the free apps have ad breaks (I know, it sucks) and the video quality is inconsistent from app to app. Sometimes it's genuine HD, other times, it's sub-VHS. I've also included links to my own reviews of some of these films.
Sergio Leone's Western
The Good, the Bad, and the Ugly (Italian: Il buono, il brutto, il cattivo, 1966) – Amazon Prime
Once Upon a Time in the West (Italian: C'era una volta il West, 1968) – Amazon Prime and Criterion Channel, Roku Channel, and Pluto TV
Duck You Sucker (Italian: Giù la testa; aka: A Fistful of Dynamite, 1971) – Criterion Channel
My Name is Nobody (Italian: Il mio nome è Nessuno; co-directed with Tonino Valerii, 1973) – Amazon Prime, Tubi, and Roku Channel
Sergio Corbucci Westerns
Massacre at Grand Canyon (Italian: Massacro al Grande Canyon; co-directed with Albert Band, 1964) – Tubi
Ringo and His Golden Pistol (Italian: Johnny Oro, 1966) – VUDU Free
Django (1966) – Midnight Pulp, Tubi, Roku Channel, and VUDU Free
Navajo Joe (1966) – Roku Channel
The Hellbenders (Italian: I crudeli, 1967) – YouTube
The Mercenary (Italian: Il mercenario, 1968) – Amazon Prime and Criterion Channel
Compañeros (Italian: Vamos a Matar Compañeros,1970) – Criterion Channel, Tubi, Roku Channel, and VUDU Free
Lucio Fulci's Westerns
Massacre Time (Italian: Le colt cantarono la morte e fu...tempo di massacro; aka: The Brute and the Beast, 1966) – YouTube, Spaghetti Westerns Draw, and Night Flight
White Fang (Italian: Zanna Bianca, 1974) – YouTube
Challenge to White Fang (Italian: l ritorno di Zanna Bianca, 1974) – YouTube
Four of the Apocalypse (Italian: I quattro dell'apocalisse, 1975) – Night Flight
Silver Saddle (Italian: Sella d'argento; aka: They Died With Their Boots On, 1978) – Amazon Prime and Tubi
Ferdinando Baldi Westerns
Texas, Adios (Italian: Texas, Addio, 1966) – Arrow, Tubi, and Night Flight
Django Prepare a Coffin (Italian: Preparati la bara!; aka: Viva Django!, 1968) – VUDU Free and Spaghetti Westerns Draw
Hate Thy Neighbor (Italian: Odia il prossimo tuo, 1968) – Spaghetti Westerns Draw and YouTube
Forgotten Pistolero (Italian: Il pistolero dell'Ave Maria, 1969) – Pluto TV
Blindman (1971) – Spaghetti Westerns Draw
Get Mean (aka: Time Breaker, 1975) – Amazon Prime and Tubi
Comin’ At Ya! (1981) – Amazon Prime, The Roku Channel, Tubi, and Night Flight
Enzo G. Castellari Westerns
Kill Them All and Come Back Alone (Italian: Ammazzali tutti e torna solo,1968) – VUDU Free
Any Gun Can Play (Italian: Vado... l'ammazzo e torno, 1967) – YouTube
Johnny Hamlet (Italian: Quella sporca storia nel west; aka: The Wild and the Dirty, 1968) – YouTube
Between God, The Devil and a Winchester (Italian: Anche nel west c'era una volta Dio, 1968) – Amazon Prime
Keoma (1976) – Tubi, Arrow, VUDU Free, The Roku Channel, and Spaghetti Westerns Draw
Antonio Margheriti Westerns
...And God Said to Cain (Italian: E Dio disse a Caino…, 1970) – Tubi
The Stranger and the Gunfighter (Italian: El kárate, el Colt y el impostor; aka: Blood Money, 1974) – Tubi
Take a Hard Ride (1975) – YouTube
Series & Double-Features
The Ringo Series
A Pistol for Ringo (Italian: Una pistola per Ringo; Duccio Tessari,1965) – Amazon Prime, Arrow, Midnight Pulp, Tubi, and Spaghetti Westerns Draw
The Return of Ringo (Italian: Il ritorno di Ringo; also Duccio Tessari, 1965) – Amazon Prime, Arrow, and Tubi
Lee Van Cleef as a Mentor Double-Feature
Death Rides a Horse (Italian: Da uomo a uomo; Giulio Petroni, 1967 – Amazon Prime, Criterion Channel, Tubi, and Spaghetti Westerns Draw, and Night Flight (beware of wildly varying image quality)
Day of Anger (Italian: I Giorni Dell'ira; aka: Gunlaw; Tonino Valerii, 1967) – Tubi, Midnight Pulp, and Night Flight
The Sartana Series (five official films)
If You Meet Sartana Pray for Your Death (Italian: Se incontri Sartana prega per la tua morte; Gianfranco Parolini, 1968) – Amazon Prime, Tubi, Arrow, and Spaghetti Westerns Draw
I Am Sartana Your Angel of Death/Sartana the Gravedigger (Italian: Sono Sartana, il vostro becchino; Giuliano Carnimeo, 1969) – Amazon Prime, Arrow, and Tubi
I Am Sartana, Trade Your Guns for a Coffin (Italian: C'è Sartana... vendi la pistola e comprati la bara; Giuliano Carnimeo, 1970) – Amazon Prime, Arrow, and Tubi
Have a Good Funeral, My Friend… Sartana Will Pay (Italian: Buon funerale, amigos!... paga Sartana; Giuliano Carnimeo, 1970) – Amazon Prime, Arrow, and Tubi
Light the Fuse... Sartana Is Coming (Italian: Una nuvola di polvere... un grido di morte... arriva Sartana; Giuliano Carnimeo, 1970) – Amazon Prime, Arrow, and Tubi
BONUS: Django Defies Sartana (Italian: Django sfida Sartana; Pasquale Squitieri, 1970) – Pluto TV
The Sabata Series (Mostly in-name-only)
Sabata (Gianfranco Parolini, 1969) – Tubi
Sabata the Killer (Italian: Arriva Sabata!; Tulio Demicheli, 1970) – VUDU Free
Wanted Sabata (Italian: Sabata vivo ou morto; Roberto Mauri, 1970) – Amazon Prime and The Roku Channel
Adiós, Sabata (Italian: Indio Black, sai che ti dico: Sei un gran figlio di...; Gianfranco Parolini, 1970) – Tubi
Return of Sabata (Italian: È tornato Sabata... hai chiuso un'altra volta!, 1971) – The Roku Channel (the only official sequel to the original film)
The Tony Anthony Stranger Series
A Stranger in Town (Italian: Un Dollaro tra I Denti; aka: A Dollar Between the Teeth; Luigi Vanzi, 1967) – Amazon Prime
The Stranger Returns (Italian: Un Uomo, Un Cavallo, Una Pistola; aka: A Man, a Horse, a Gun and Shoot First, Laugh Last; also Luigi Vanzi, 1967) – Amazon Prime
Sadly, the third official Stranger movie, A Stranger in Japan (Italian: Lo straniero di silenzio; aka: The Silent Stranger; also Ferdinando Baldi, 1968) isn’t available to stream anywhere
Other Zapata Westerns
A Bullet for the General (Italian: Quién sabe?; Damiano Damiani, 1966) – Tubi, VUDU Free, The Roku Channel, and Night Flight
The Big Gundown (Italian: La resa dei conti, 1966) – Criterion Channel (note: this is a must-see that hasn't been available streaming until now and it probably won't last long)
Run Man Run (Italian: Corri uomo corri; Sergio Sollima, 1968, note that this is a sequel to ) – Amazon Prime, Tubi, VUDU Free, and Night Flight
Tepepa (Giulio Petroni, 1969) – Amazon Prime
Other Good to Great Films
Taste of Killing (Italian: Per il gusto di uccidere; Tonino Valerii, 1966) – VUDU Free
Requiescant (aka: Kill and Pray and Let Them Rest; Carlo Lizzani, 1967) – Amazon Prime, Tubi, and Tubi
Django Kill...If You Live, Shoot! (Italian: Se sei vivo spara; Giulio Questi, 1967) – Amazon Prime, Tubi, The Roku Channel, VUDU Free, Pluto TV, and Night Flight
Gentleman Killer (Italian: Gentleman Jo... uccidi; Giorgio Stegani, 1967) – Spaghetti Westerns Draw and YouTube
Man, Pride & Vengeance (Italian: L'uomo, l'orgoglio, la vendetta; Luigi Bazzoni, 1967) – VUDU Free and Tubi
A Long Ride from Hell (Italian: Vivo per la tua morte; Camillo Bazzoni, 1968) – Amazon Prime and Tubi
Today We Kill, Tomorrow We Die! (Italian: Oggi a me... domani a te!; Tonino Cervi, 1968) – Fandor
Black Jack (Gianfranco Baldanello, 1968) – VUDU Free
A Sky Full of Stars for a Roof (Italian: ...e per tetto un cielo di stelle; Giulio Petroni,1968) – Amazon Prime
Cemetery without Crosses (Italian: Une Corde, un Colt; aka: The Rope and the Colt; Robert Hossein, 1969) – Amazon Prime, Arrow, Tubi, VUDU Free, and Night Flight
Django the Bastard (Italian: Django il bastardo; aka: The Stranger's Gundown; Sergio Garrone, 1969) – Tubi and Spaghetti Westerns Draw
The Price of Power (Italian: Il prezzo del potere; Tonino Valerii, 1969) – YouTube
Hanging for Django (Italian: Una lunga fila di croci; aka: No Room to Die; Sergio Garrone, 1969) – Spaghetti Westerns Draw
The Unholy Four (Italian: Ciakmull - L'uomo della vendetta; Enzo Barboni, 1970) – YouTube
His Name was King (Italian: Lo chiamavano King; Giancarlo Romitelli, 1971) – Tubi
Shoot the Living and Pray for the Dead (Italian: Prega il morto e ammazza il vivo; Giuseppe Vari, 1971) – YouTube
Cut-Throats Nine (Spanish: Condenados a vivir, 1972) – Midnight Pulp+ and Tubi
Grand Duel (Italian: Il grande duello; Giancarlo Santi, 1972) – Tubi, VUDU Free, Spaghetti Westerns Draw, and Night Flight