I had heard a lot of positive buzz about this game from friends abroad so I made a birthday present out of it to a dear friend. We had a great time playing it, and the humour of the cards is certainly something we had never seen the likes of in a game before. Definitely one of the best aspects of Munchkin.
I am very glad I got the Deluxe version because I recently played with someone on the strictly card version. Having the board and the colorful figures to keep track of your progress is a significant improvement, and only the Deluxe version contains them.
One word of caution: the game can become a bit predictable over time. We find that it always goes like this: a few rounds where we all amass races/classes/weapons in order to improve our character, then the moment someone starts advancing ahead, we all turn against them, cut that player down to size, then someone else is on top, and repeat. It becomes a bit of a long struggle till someone gets lucky with the cards and they win. Unfortunately the only way to counter this is to indulge in one of the gazillion expansions for this game every now and then.
We don't play Munchkin much anymore ourselves, but I know others who love the game to bits. I think ultimately it depends on how complex you like your games, but personally, while I am not in love with Munchkin anymore, I am still fond of it.