At the risk of sounding snobbish, I stay with champagne. I’ve found a number of really nice bottlings that are available at around $25 (US), so I don’t really look for alternative sparklers. My favorites right now are:
1. Philippe Prie Brut Tradition – $24
2. Philippe Fourrier Carte D’or – $24
3. H Blin Brut – $28
4. Heidsieck Monopole Blue Top – $25