WTF! The cheapest looks like the best deal because of Hitman 3. They're all PowerCooler, all have 256-bit memory, and same core/memory clock speeds. It doesn't look like there's a lick of difference between the 3 cards to me (Assuming NewEgg has mislabeled anything).
ATI's Catalyst drivers work with all ATI cards, so that's not an issue. The OEM is an issue because, as others have stated, ATI has a really good 3-year warranty program. OEM's card have also sometimes been clocked at lower speeds than retail cards (But those specs are 9800PRO specs).
Last week, however, Best Buy had the the Pro on sale for 229.99 with 50 MIR (179.99). And this was the ATI-Branded box:(
Edit: Reread the thread. Unless you can verify that PowerColer offers 3 year warranties, I wouldn't assume that's what you're getting with the retail version. The 3 year warranties from ATI apply to the BUILT by ATI cards. The Powered by ATI cards are subject to vendor's warranties... I.E. Whatever PowerColor's policy is.