Memory: Mushkin Silverline 8GB (2 x 4GB) DDR3-1333 Memory
Hard Drive: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive
Video Card: Sapphire Radeon HD 6870 1GB Video Card
Case: Cooler Master HAF 912 ATX Mid Tower Case
Power Supply: Antec 550W ATX12V Power Supply
Optical Drive: Sony AD-7280S-0B DVD/CD Writer
Monitor: Asus VH238H 23.0" Monitor 1920x1080
Operating System: Microsoft Windows 7 Home Premium SP1 (64-bit)
Keyboard: Gigabyte Force K3 Wired Gaming Keyboard
Mouse: Gigabyte GM-M6880 Wired Laser Mouse
I'm just poking around for any advice on parts and such. But mostly I'm wondering if my monitor and GPU are a good combo, I've heard the monitor comes first, then decide on a GPU. So I'm really not so sure about the combination.
CPU cooler is good, but the hyper 212 Evo is even better for $10 more. You might have trouble with some games on high/ultra settings with an HD 6870, like BF3 for example, but you should be able to run nearly any game on at least medium settings. Since you seem to have an ample budget, what would you think of this GPU...
If you have more money to spare, I would recommend upgrading the graphics card to either the 7850 or the 670.
The way I see your setup right now, you won't have to upgrade for a very long time, everything except your gpu. The 2500k will handle any game in the next decade probably, 1920x1080 is widely supported resolution, and your case, psu, ram are all good. The 6870 is a great graphics card, but it doesn't max out on 1920x1080. If you don't mind playing some games at mid-upper settings, then it's a good choice. However, if you want to play every game coming out without ever having to worry about adjusting graphics settings, then I would recommend upgrading to 7850 or 670.
Another suggestion would be to ditch the keyboard and mouse, unless you specifically like those two. They aren't all that different from the old Dell keyboard and mouse.