Since I take a chance with every theme I download, I am looking for a theme that runs on 98. Some people use litestep on older systems you know :). SInce I still do not have the graphical knowledge to make one for myself, I am looking for one that works on 98, that is fairly good and recent.
Anything that has transparency is not 98 compat. Everything else for the most part should be.
Well, most 'recent' themes, are xp/2000 only, so you'll have to look at older themes. My two favorite themes (besides my own) are pretty old (ots1 themes converted to ots2) and I'm pretty sure, 98 compatible: Thin and LiteGnome4
The recency of a theme should not limit your decisions. Many of the somewhat older themes are still better than most that have been released recently. My favorites were RhodiumEdge and Amiga HLE. If I recall correctly, they have both been updated to the OTS2 standard. ClassicLite (lol) should work too. ;)