Fantastic! The one where Snape shot bread sauce out of his wand in the wrong direction was priceless.

With James, it's just too damn satisfying to be able to take him down a few pegs, no matter what the contest.

Amen! It's no fun playing games with someone you always want to beat. Besides, it wouldn't hurt to boost Severus' self esteem, whereas James already has an over inflated head. So James would probably get an even more unbearable ego if he beat Lily at games. :P

In fact, there are things he's done that she doesn't even want to know how they were achieved.

LOL! What might these things be, I wonder?