This is a hard question for me to answer, since I like every WCA event. If what I practice most would equal my favorite events, it would be:
1.) 3x3
2.) 5x5
3.) 2x2
...but I also like megaminx, square-1, OH, and 3BLD even though I don't do them as much
In that order
Order is subject to change, but the list itself isn't.
Actually, I dunno. 3BLD is kinda fun but I've never actually committed to getting good.
If Feet officially gets removed, it might take its place, but probably only after a while and only if I ever actually start putting effort into it.