I currently have a HD7 from T-Mobile, and I love the device. The specs could be a bit better (mostly the screen could be a SLCD) but apart from that I love the phone. If you do want better screen quality, go for the HTC HD7S, with a Super LCD screen. I would not go with the Dell Venue Pro though, some users have issues with it and from what I remember have had trouble updating it?
Either way, I would go the HD7 or the Radar (in that order)