Check out the HD scoreboard at the Dallas Cowboy Stadium.

http://www.engadget.com/2009/09/28/dallas-cowboys-hd-scoreboard-makes-the-guinness-book-of-world-re/

Check out

MetaTwistTower @ Munich Airport: http://www.3mgtg.com/en/public-space-solutions.html

JCDecaux @ Changi Airport: http://www.jcdecaux.com.sg/wp-content/uploads/2014/10/jcdecauxdigitowers.html

Hi,

The wild project : http://insitu.lri.fr/Projects/WILD, and the reality deck http://labs.cs.sunysb.edu/labs/vislab/reality-deck-home/

http://labs.cs.sunysb.edu/labs/vislab/reality-deck-home/

http://insitu.lri.fr/Projects/WILD

Check this out, ORNL's Everest display system

https://www.olcf.ornl.gov/computing-resources/everest/

As Guillaume suggested, the Reality Deck (disclaimer: which I've worked on) is, to my knowledge, the largest facility in terms of total pixel count (and probably display device count and floor space). We recently published a paper in IEEE CG&A which includes all the details that you're looking for. In summary, we've got:

416 LCD panels in a 4-wall arrangement, each panel being 2560 x 1440 resolution

1.5 gigapixel aggregate resolution

18 + 1 node visualization cluster with 4 GPUs each

Other note-worthy systems that haven't been already listed are the Stallion Powerwall at the Texas Advanced Computing Center (about 300 megapixels), the various HiperWALL installations (I believe about 200-300 megapixels), the CAVE2 (about 60 megapixels iirc but with passive stereo and immersive)

Hope the above is helpful :).