I've played Magic once, about 3 years ago. I was more heavily into Marvel Over... Oversomething (forgot the name, and I keep getting it confused with Overworks :P ).
Edit: OVERPOWER! That was it.
I also tried to make a Sonic card game myself with a bunch of Sonic Powerzoners a few years back, but without a programmer, that game is now sitting on its behind, stagnating.