The best ceviche I've had is on the beach in Mexico. Freshness makes a huge difference. I've tried it in a number of places in Austin.
Dona Emilas - best so far
Saba - OK, more fruit than fish, though
Curra's - better than Saba, not as good as Dona Emila's
Other places - I don't even remember them, so probably worse than Saba
Any other places I should try?