Well, first of all make sure you're using the 1.15 BETA patch, as there were apparently EXTREME problems with the forbidden palace.
Now, as to mods...some mods I like include Tethurkan's Test of Tme mod (be warned, if you play the all-cities version, you might as well make your dinner in the mean-time

) and the Mediteranean Mod. TEThurkan's mod includes an accurate map, capable of holding all 31 civs I think. The mediteranean mod is, obviously, an accurate mediterranean map/scenario. If you're looking for a change in graphics, sn00py's made some fairly nice looking terrain sets, as well as Warpstorm's watercolour terrain.
If you just want balance fixes (in the author's opinion, of course), player1's mod and the Apolyton University mod make decent changes without altering the stock rules much, especually player1's. The latest AU mod, however, has some changes that, though for the better, deviate more significantly from the stock rules, so if you don't want anything radical go with player1's.
That's all I've got for now. Good luck on your games