This one. Use coupon code TP2GK4X1DTX0C8 (expires June 3) during check out. It comes out $229 + tax (after $50 mail-in rebate). Slightly cheaper than Amazon ($290 after $50 main-in rebate). Dell also offers Nokia N85 at $247 + tax (with $50 main-in rebate).
Reviews: GSMArena; BrightHand.
Discussions “N85 or 5800XM”: phonegg; Nokia discussion forum.
A thousand words 