I have an HTC 8X and really like it.
However, the Nokia Lumia lineup are generally the "must have" WP flagships. Ex-Microsoft employees pretty much run Nokia's mobile division now, so it's as close as you'll get to an honest to goodness Microsoft phone.
The Lumia 1020 is the new kid on the block with a crazy camera, but the 925 and the 928 are close runners up (the 925 being the better one, according to Nokia).