This for sure is my favorite movie. What I really love is that there are jokes, puns, movie references & all almost all the time, and that, unlike in a lot of big production movies, can easily go by unnoticed. That's why even if I've seen this movie tons of times, I still can find some new ones. That's also why some people say you should watch it several times to really find it funny. Actually the best thing to do is to watch it with the remote in your hand, to be able to pause at any time to read all the stupid things that have been hidden.
I don't know about the translation, but I bet watching it in any other language than French must ruin quite a lot of puns. Also I don't know whether all the stuffs written in the different scenes are also translated.
I know a lot of people who just like me have watched that movie over and over and know most of the script by heart, and would from time to time repeat some of it in real life. You can also find tons of references of the movie all over the Internet, in blogs and comments.
On the other hand, I know of people who just find that movie quite poor, without any interest, and I can understand them. The jokes are quite often stupid like "(showing a picture) Is this your husband?" "No it's my dog." "Oh yeah, of course...Talk to me about him." "He was a really nice dog..." "No, about your husband". Of course it's stupid to ask whether the dog is her husband, and of course it's stupid to tell about the dog. So some people will definitely find this movie stupid, but others, like me, will like it. Just a note about the jokes: they may be stupid, but unlike in some movies, they are not gross.
So eventually, if you're French or have a really good French level, and feel like the previous joke can indeed be funny, you definitely have to watch that movie. If you find it lame, don't. As for if you don't speak French but still find that joke funny, well, just keep in mind the movie won't be as funny as it should be, but it should still be quite funny.