I'm playing the KOF games. Moreso, KOF 98 aka KOF Dream match and KOF Evolution.
Both games and the others in the series are really nice, but the bosses I have fought, in both KOF 98 and KOF Evolution, are cheap as heck, even on easy mode.
After playing a few KOF games, I kinda understand why people highly rate KOF 98, over the later entries.
The dreamcast versions of KOF, have 3d backgrounds and objects. But I have to admit, the two european clock tower stages in KOF Evolution, with the wooden people statues, are amazing too look at. Like holy crap, those two stages are lovely.