HP 2311gt

Pros: No flickering because a passive polarized filter is used.
The 3D glasses are light, low cost and no batteries.
Works with common graphics cards (mid-range).
Works with most games that use DirectX 9, 10, or 11.
You can take 3D screen shots.

Cons: Although there is a VGA connector, it can't be used for 3D viewing.
When is 3D mode, the effective resolution is reduced.
Some people may find 3D viewing causes eye strain.

Summary: I haven't seen any lower cost implementation of PC 3D graphics. With a 1080p display, you get a nice crisp image and you have 3 types of video connectors (HDMI is recommended for best results).