I think beating FFX-2 without killing myself (for real, not in the game!) is something of an achievement.

Seriously, I was very proud to beat Ozma, at long range (I missed a lot of the Friendly Creatures), in FFIX. It was an extra memorable day for me as well, because it was also the same day my friend's eldest, Taylor, was born. ^_^

FFVIII was also very challenging for me. On my first play through I found I wasn't strong enough to defeat Adel and Rinoa kept dying on me (oh well...) Worse still I only had one save block (the rest of my card was full) and I couldn't level up as all the monsters offered little EXP, and I couldn't get out of the Lunatic Pandora (Quistis kept whining: 'We can't leave without Rinoa!!!!' or something). So I had to start over. This time I levelled up and put suitable Junctions on Str.

Also, killing Ultimecia was a big deal for me, as it took me ages to get the strategy right. I thank the wonderful Piggyback guide for that.