Batman 66 is a great game. It's got a bit of clunk but some great rules. The theming is well done and really hits home with alot of people too. It is a Stern so you do get that quick and cheap feel, but it's a well made game.
Medieval Madness is an ALL TIME CLASSIC for a reason. Great rules, shots, toys, sound (amazing voice work). The comedic medieval times theme with the dragons, princesses, castles and kings is timeless. The remakes are very faithful and well made. The color upgrade is fantastic.
I don't think you'll go wrong either way, but MMR all day for me.