If you analyze the underpinnings of the "Good Luck" wish, of course you'll see some things that are contrary to what you, the player, wants to happen. *Of course* you want the good luck, good rolls, and good everything to come YOUR way, and not your opponents.
But if wishing "good luck" to your opponent bothers you, then you might already be setting yourself up for defeat, because you are already thinking that you're "wishing something away" that you yourself want. Instead, who's to say you're not wishing "good luck" to your opponent, "because he/she is gonna need it to play you?!?" Why not look at it that way? Why must you focus on the negative aspect of "good luck" and not the positive?
And if you still can't get past it, why not use something else?
How about:
1. "Play well!"
2. "Let's have a good match!"
3. "Let's have some fun!"
Or how about the sneaky killer:
4. "I would normally wish you good luck, but I'm the one needing it to play you!"
(This one is very sneaky! You're falsely flattering your opponent, and he/she will be caught off guard when you come out of the gate with your cannons blazing.)
Use some psychology, but don't be disrespectful, sarcastic, or otherwise cheap.
Hope this is helpful,
-Sean