Ultima?
Yes, but NO.
Flare?
Harumph. Not even as good as Ultima.
Cure 3?
Damn fine, but no.
Life 2?
You're getting close, but still no cigar.
Quick?
*snore*
C'mon people, the best spell in the whole game is.... OSMOSE!
That spell was a LIFESAVER in the Final Battle. I only wish I had all my characters learn it before. The best part is, compared to the other FF's, you get it WAAY too early, and it's uber-powerful (usually).
(Of course, I'm a little biased due to the fact that I forgot to stock up on ethers before Kefka's tower. But still, dude.)