I have a few favorites, all of them fairly hard to find, but SF is one of the easiest places to find anything bubbly
Adolfo Lona Brut Rose generally $10-14 Brazilian, delightful light, hard to find
Graham Beck Brut Rose about $15 Very good South African
the best for last (i.e. cheap and tasty)
Veuve du Vernay Brut Rose (I googled this and found it in SF at K&L for $6.99
This one is a French one, but made from Tempranillo, a fairly unusual grape in France

All my choices are Rose because I much prefer roses in inexpensive sparkling wine because they carry far more complex and pleasing flavor than do cheap whites, IMHO anyway. There are a host of new California options too, but I've tried few of them so cannot comment.