and as far as 4x4's ive heard really good things about meffert's, and i do know that the rubik's revenge is absolutely awful, it has the amazing ability to lock up for every single turn that u attempt to make
im not sure how good ur computer is so heres a couple that you can try(fair warning: some of them really suck :p)
@Regisiew: I really all comes down to personal preference between stickers or tiles. Some people don't like the feel of tiles, but I prefer them over stickers. Tiles do last longer than stickers though. I love the smooth tiles i got from cubesmith. :) (im sure if u do a search you will find...
and theres always just standard oll and pll :)
(ive never really looked at mgls so i really dont know anything about it, except that it orients all the ll corners and one in the bottom layer)
btw slncuber: CaptainCrash44 (ErikJ) has a good video on mgls if ur interested