I have KRK RoKit 5s and have enjoyed them. The 3rd generation model recently came out so you could get a pair of the 2nd generation ones for $200 ($100 each). They used to be $150 each. Pretty good deal.
http://www.bhphotovideo.com/c/product/567755-REG/KRK_RP5G2_RoKit_5_G2_45W.html
+1 on these, they are what I use at home. The only negative is that the amps have noticeable self-noise in a very quiet room - i.e. you may notice a faint hiss. For me, one of the two has this more than the other, but not enough to make me think it's anymore than manufacturing variance. Yes, I have verified this with different sources, etc. The noise is still WAY lower than with other cheap monitors I've used, like those from M-Audio and Alesis, both of which I'd stay away from.
Do yourself a favor, and put these up on stands instead of on your desk. I have the QuikLok ones that are linked on the B&H along with Auralex MoPads (were a package deal from Sweetwater). Then you can really get the most out of them when they're placed at the correct hight/angle.