For some reason, Sony still sticks to Adreno (just like HTC). Samsung always goes with PowerVR SGX and Mali. The best phone in terms of smoothness of UI is undoubtedly iPhone, and they stick with PowerVR SGX as well. Only a handful use Tegra and these are usually the laggy Honeycomb tablets in general (but best in games).
Does those facts somehow deduce who's the best GPU?
LG-D820 & ME571K on KOT49H
ST25i on Stock JellyBean 4.1.2 V6 lite
A1395 on iOS 7.0.4 | A1432 on iOS 7.0.2