Yes, Chimay is a classic. I've also tried all three (the white, blue and red). The Blue is my favorite.
If you like this style of beer, you must find one called "Rochefort 8." It is also a Trappist beer brewed by Monks. It's a Dubbel style that's around 9% ABV. It is my absolute favorite Belgian beer and it has a complex, semi-sweet darkness.
Thanks for sharing this with me. Let me know if you find the Rochefort or any other great beer that you enjoy.