Hmmm... my history looks a little like this Samsung Admire> Sony Xperia Arc> Samsung Galaxy Indulge> ZTE Warp> Sony Xperia Mini> Pantech Burst> Nexus 4
The Nexus 4 is easily the best phone I've had. The Arc and Burst were probably the next closest. When I go the Arc it had MIUI installed it ran pretty smooth. The Burst was pretty smooth as well, but there were little hitches here and there that were a bit annoying. The Nexus has been the smoothest phone I've had so far.