Joe Jusko's Marvel Masterpiece set is probably my favorite. Like you, KT, the artwork blew me away, since at that time, there had never been card art quite like it. I still like his artwork the best in the '93 Masterpiece set as well. That set was kind of a letdown overall, IMO. I love Jim Lee's X-Men set too. I think that was the first full set I owned as a kid.
Actually... I think the 1992 MM, X-Men, and Marvel Universe sets are the most nostalgic for me, since they were the first cards I can remember getting at the local grocery store every time I went.
I had a lot of cards when I stopped collecting, which I think was 1995, as I'm pretty sure the 1995 X-Men series was the last set I tried to collect in the 90's. I ended up selling all of them on ebay about 7 or 8 years ago. Then, my manager at work gave me the 1992 Marvel Universe set as a birthday gift after we were talking about collecting Marvel cards as kids. The nostalgia was intoxicating and it sent me on an ebay spree. I bought back every set I had sold and then get several others I never had, as well as several subsets, or "chase" cards. They're all in 9-card page sleeves (1 card per pocket). I really should do an inventory sometime.