Nah, there are loads of 8-bit and 16-bit characters which have worse boobs than Tifa.

Seriously, though - it all depends on which Tifa you're talking about. Tifa on world map, Tifa in cutscene, Tifa on the date, Tifa in AC, Tifa in CC... all are different.

But if you're going to pick out the worse ones, they're no worse than a pixel or two sitting on the front of an 8-bit character's chest.