HTC

I'm not an HTC fan. I think they have always made crap and are just making better crap now. Samsung makes some quality stuff, but the Super AMOLED is theirs and aren't going to share it with anyone. HTC does have a pretty cool interface, but their devices are buggy and have horible battery life. LG makes quality devices, however, their specs tend to be behind everyone else. Motorola pushes the industry with high spec phones, but their tech is hit or miss.
In the end, I go for Motorola first because I am the technophile and want the coolest phone with the best features. Second, I pick LG. Not the coolest, but reliable. Samsung is doing a lot of things right, so they are not out of the question. I'd put them second, but their specs aren't as good as Motorola and their dependablility is not as good as LG. HTC comes in last. While they are first out of the gate they finish last. UI is really all they have going for them. The Thunderbolt is already having headphone and battery issues.