Personally, I'm more than happy with my combo of Microsoft's sidewinder x4 + revoltec's fightmouse elite. Both wired, so no weird interference with my WLAN card (both of them work on the 2.4GHz band typically). Also, once you tried a mouse with ceramic feet... you won't be going back. Using this mouse for 2 months now and other mice just don't move as smooth. Got the keyboard about 2 years ago and it's not showing any signs of wear so far.

I stopped using logitech after they started making all the weird layout changes. Like the neat "let's combine scroll lock and print screen on one key" making taking screenshots in ffxiv impossible. Or the drivers blocking me to use the media keys in foobar2000, so that I either had macros or media keys working. Or, best example yet, changing locale to Japanese crashing the logitech drivers on boot. Logitech [no, thank you].

I didn't hear much good about Razer either, a friend of mine had the whole coating dissolve on him after half a year, it looks like someone went over it with sandpaper.. and it cost him like 120€