2560x1600 in the center(HP LP3065). Absolutely awesome for everything, especially text. Though sometimes a tad too large for gaming. All my computers switch to this one through an Avocent SC8 KVM switch.
On the left 1920x1200(LP2475w). My main workstation's task bar is on this screen(5 rows high). The main workstation has a dedicated mouse and keyboard, so I can always instantly interact with it. The slightly larger pixel pitch keeps it readable even though it's a tad farther away, but is otherwise slightly sub-optimal. If money was no object I'd probably replace it with another LP3065.
On the right 2 2048x1152(Samsung 2343BWX mounted one above the other), give me a lot more pixels, for a lot less money, at a nearly identical dot pitch to the LP3065. They spend 99% of the time switched to the main workstation. Sometimes their poor viewing angles make things a little harder to read. Again, if money was no object they'd be replaced with another LP3065.
All 4 monitors are mounted on monitor arms attached to the wall. The 2 Samsungs share one arm. It gives my desk has plenty of room for keyboards, mice, powerstrips, and piles of paper. The main workstation drives them all with a Sapphire Radeon 4850x2, which has 4 DVI outs.
My setup is a bit of a hodge podge but I love working and playing with it.
