HP Pavilion 27xi
As long as you have no advanced demands, the Pavilion 27xi will meet your basic needs with aplomb.
HP 2311xi's impressively wide viewing angle, useful connections, and low price make it an easy monitor to recommend.
The HP 2311gt is a fairly cheap way to get decent 3D on a monitor. It's also capable for general-purpose use, with useful connections and OSD options.
The HP ZR2740w sacrifices customization to deliver a powerful monitor at a reasonable price.
The HP 2311x is a great monitor deal, with good performance and a great assortment of connections for its price.
HP x2301 Micro Thin LED monitor
The HP x2301's low price, good performance, and sound design make it a new high-water mark for budget monitors.
The HP ZR30w lacks too many features to be competitive with other, lower-priced 30-inchers.
HP DreamColor LP2480zx
The HP DreamColor LP2480zx is a performance monster that costs too much for the features it offers.
The HP 2709m's lack of features makes it less desirable than HP's own similarly priced w2558hc.
The HP w2558hc is jam-packed with features and well worth its asking price.