If youre going to be gaming mostly - then Samsung E6500 because it handles Image Retention ALOT better than Pannies.
The ST50 has way better blacks/contract (ive had both) and is SILENT ..but since your playing games mostly the Samsung buzz might not get to you. Right now i'm personally thinking of switching back to Panasonic despite the IR becuz the buzz is just too annoying (its not overly bad - but i live in an apartment and when the volume is lower and theres dialogue or quiet scenes the buzzing sounds like bees sometimes)
Performance wise theyre both good - really good, but i find the ST50 has more pop only becuz of its superior black levels. I've learned there is no perfect TV right now...maybe the Samsung F8500 or Panny ZT60 but both will most likely be out of my price range
ST50 > E6500 for sure PQ wise..so i dont think E6500 can even compete with the GT/VT series. And if E6500 is the same as E8000 - then ya...2D PQ award goes to Panasonic for sure.
TV: 65" Sony OLED XBR65A1E Speakers: KEF LS50 LCR Front Stage Subs: SVS PB2000 & PB1000 [B] AVR: Denon X3300W DSP: REW with UMIK-1