Congrats. I tried to do that once, got all the ultimate weapons (Blitzball was the worst, it took a whole Saturday), and than decided to give up, when I realized how much grinding there would have been involved.
Which ultimate weapon was the worst for you? Butterfly dodging was also very annoying, but it took way less time than Blitzball.
The chocobo race, easily, hands down, no contest. Everything else either has an exploit* or can be completed eventually with enough time. Getting a time of 0:0 in the chocobo race is down to pure dumb luck. Anybody who says otherwise probably got super lucky and completed it within ten minutes. It took me about an hour and a half, and I was expecting it to take longer than that, honestly.
*(Speaking of, I don't know if this holds true in the original, but in the HD versions of FFX there's a super easy exploit for the lightning dodging:
Basically, there's a certain crater in the southern half of the Thunder Plains that will always trigger a lightning bolt after you walk through it once. From there it's just a matter of patience.)