There's many entertaining films outside the obvious classics. I watched quite a lot gialli lately but had to stop after they started to get mashed up in my head, all Ivan Rassimovs and George Hiltons looping in every film...Anyway, I would highly recommend Antonio Bido's Watch Me When I Kill and The Bloodstained Shadow. They are not usually ranked that high, but I think Watche me... was very bleak and well done. Bloodstained... has great locations and likable main couple, it's a solid giallo.
Strip Nude for Your Killer is worth seeing just for the most miserable sex scene ever filmed: fat, impotent guy tries to cheat her wife with a prostitute, but fails to get an erection and starts to cry mommy in the middle of the act! Then he wanders around his apartment, crying, with a sex doll on his hands. He even talks to the doll "You are the only one I can have sex with". Amazing...
The two Death Walks films were a bit boring for me. ...at Midnight was the better one of the two. But it's more like a crime film than giallo. Anyway it stars stunning Nieves Navarro and there's a cool gang of bad guys.
Autopsy was a great surprise. Morbid and unique atmosphere. Morricone's eerie music is similar to The Short Night of Glass Dolls.
Killer Must Kill Again was also one the better ones. Unique plot, very dark and interesting characters. It's also surprisingly well directed by Luigi Cozzi, even though he's more known of his trashier efforts. I would definitely buy this on Blu-ray if it gets released some day.
