I like .TGAs, mainly for the alpha channel. I want max quality too, and .TGAs are good for that. You can't edit your textures many times and they do not degrade like if you would edit .JPGs many times (which of course you should not do, but keep .PSD and save that out as .JPG, but ppl tend to be lazy...). What HD space they take is to me irrelevant... anything under 100 megs (whole game) is OK :)