They are rather strong on innuendo and fan service, but have some of the best fighting systems out there.
SRTOGSEF is a classical RPG with very ugly/old-school map exploration, reminescent of 8-bit era. The combat system is 4 player + assists and crazy over the top boob jiggling fullscreen animations.
Project Cross Zone plays like a SRPG, and wasted about 0 seconds on exposition or character introduction. Lots of jokes (not as much as SRTOGEF) and mostly, lots and lots of fighting and action. Great game to play in the subway/bus while I go to work.
Namco X Capcom intro video:
Youtube Link
Project Cross Zone intro video:
Youtube Link
Really can't think of many games with a line-up this epic. I'd list some of the coolest ones, but then I think I'd just list them all...
Both games have a fighting engine similar to the one in Valkyrie Profile, where you juggle attacks and enemies by pressing buttons at the right moment. Press too soon and you cancel early, losing on damage. Press too late and enemy brings back a "damage shield" that prevents N attacks. Press at just the right time, you get 100% critical rate, etc.
If you love crude jokes, cute anime characters, over the top combat, gundams and the Valkyrie Profile combat engine, those two games are like a bounty chocolate bar; "A taste of paradise" ?