Other Euro-Westerns from the period I recommend:
A Pistol for Ringo &
The Return of Ringo starring stuntman Giuliano Gemma as a wily, roguish gunfighter - in the first film after being arrested, he's asked to infiltrate a hacienda where an outlaw gang fleeing a robbery gone bad have invaded and taken hostages. In the only official sequel , Ringo returns from having served in the Union Army and been thought KIA to discover an army of Mexican banditos have taken over his home town, in a storyline that was inspired by Ulysses' homecoming in the Odyssey.
Gemma also starred in
Day of Anger, along with Van Cleef. Gemma plays a street sweeper who ends up the protégé of Van Cleef's master gunslinger.
God Forgives -- I Don't!
The first film Terrence Hill (Mario Girotti) and Bud Spencer (Carlo Pedersoli) co-starred in, leading to their appearances in increasingly comedic Westerns like the Trinity films and eventually buddy action-comedies like
Look Out, We're Mad!
Ace High
Hill & Spencer return and face off with a wily criminal, Cacopoulos, played by Wallach and they end up in Mexico during a time of revolution and it gets into grim Zapata Western (i.e. spaghetti westerns set usually during the Mexican Revolution of the 1910s) territory.
My Name Is Shanghai Joe - a Chinese immigrant must utilize his kung-fu after he discovers the ranch he's found employment at isn't involved in moving cattle but Mexican laborers being sold essentially as slaves. A gory, trashy vibe but with a beautiful Bruno Nicolai soundtrac.
Four of the Apocalypse - one of Lucio Fulci's offbeat Westerns as a quartet of petty criminals wander the wilds of Utah together and run afoul of a sadistic bandit played by Tomas Milian.
The Sabata trilogy directed by Gianfranco Parolini. Starring Van Cleef as a professional gunman in the first and third installments. The second was originally to be a film entitled
Indio Black but swiftly turned into a Sabata film to capitalize on the popularity of the first which had inspired lots of imitators. It starred Yul Brynner (Van Cleef was already committed to starring in one of the Magnificent Seven sequels).