I know he was in kill bill and i saw some of his films accidently searching through you tube are they any good ?

Well Street Fighter is a must watch (if you haven't already seen it). I've seen four of the SF films he is in and the first is by far the best. He plays a great anti-hero. Quentin Tarantino put mention of this film in True Romance.

Definitely check out The Shogun's Samurai, aka The Yagyu Conspiracy, and Samurai Reincarnation, both directed by Kinji Fukasaku. Classic samurai fun.

i also recommend the old school stuff from the 70´s and 80´s
like Ninja Secret Scroll or Legend of the 8 Samurai...

Chiba films are VERY inconsistent in quality. The first STREET FIGHTER film is a classic though, and the first EXECUTIONER very good (sequels to both mostly sucked). KARATE BEARFIGHTER is the best of his Masu Oyama trilogy (but not the first). The first YAKUZA DEKA film is worth a watch (still haven't watched the second). Chiba's appearances are probably the highlight of the first SISTER STREETFIGHTER film.

Avoid G.I. SAMURAI - one of the biggest wasted opportunities of cinema!

Other than that, I'm struggling to think of any Chiba films (as opposed to films in which Chiba was somewhat involved) that I'd recommend to anyone except true fans - though there's plenty I haven't seen.

I'd certainly recommend Sonny Chiba in the film Golgo 13: Kowloon Assignment. It is a little dated (1977 I think) but he is super cool and I think it lived up to the manga and anime versions of Golgo 13.
Just a word of warning, there are several edits of this film available, including a badly dubbed and cut version, avoid that version like the plague!