I assume you also want them to be cheap, so I will not recommend an Aosu or HuaChuang
I just bought a Cyclone Boys 2x2 Stickerless. It's really good out of the box (I just created a thread for this in the Puzzle Review forum where I give a bit more detail).
Regarding 4x4, you have the YJ Yusu stickerless (it's the pink / candy stickerless color scheme, though). If you want a more standard color scheme you will have to get a Cyclone Boys G4 but I've heard you'll need to set it up and lube it before it's good.
On 5x5 I don't know of any cheap, good & stickerless option. Maybe CB will make their new 5x5 in stickerless version soon.