XCell SureLock Mini Gel apparatus, and precast gels
I know that buying precast gels is lazy, but these are great. I'm all about the laziness when it comes to getting beautiful data on perfect gradient gels. These gels will allow you to do science without worrying about spilling unpolymerized acrylamide-bis mix on your arm and learning all about neurotoxins. Invitrogen also usually has an ongoing program where if you buy five boxes of gels, you get a free gel apparatus. The gel apparatus rarely leaks due to some nice engineering/design upgrades to the apparatus.