Not a big champagne guy but I always drink it during celebrations and holidays. My favs:
Veuve Cliquot Yellow Label- above average taste, easy to find, low/moderate price. Perfect for those times when I decide to get a bottle 2 hours before a get together.
Krug NV- had this on NYE... very good. Given the level of wine stores in my area, tough to find. I think I paid $70 for a 375ml.
Bollinger NV- a little less enjoyable than the Krug for my taste buds. Same problem with Krug for price/availability though.
I had plenty of other $30-50 bottles when trying to find one for my wedding reception last year, but none stood out enough to recall now...
Would love to try a Krug Rose or DP Rose one day. It'll have to be a day when my wife has no way of discovering the purchase price