hmm... the only adventure games well translated I can think of are Curse of Monkey Island and Grim Fandango. Sorry, it's a bit old...
CWallaby55> I don't know how is the Syberia's translation, but I finished Syeria 2 several months ago, and the french version is not very good.
For Sam&Max, I read two tests of the french translation (made by pro websites) and they find the translation great. The only real complaint is not about actors, but about bugs (typo, cut, untranslated sentences).
I watched a short video of the cheese episode, translated in french, and it appears to be a very great job to me
