I feel like I've been recommending this to everyone lately, but the Mavic Open Pro laced to an ultegra hub is a pretty awesome wheelset. It's nothing special, and it's not ultra light (around 1800g, I think), but they're tank wheels that'll last a good long time. Plus, if you're tech saavy, the Ultegra hubs are not sealed bearing, so they're pretty friendly to being user-serviced.
+1. I've got this setup on my CAAD9. I've only been doing this for three years, and based on recommendations from various quarters I bought a set. The only bad thing I've heard about them is that they're relatively heavy. I like the idea of thirty-two spokes/wheel, since I'm a relatively heavy rider (6'2", 200 lbs). You can get them for $250-$450/set, depending on whether they're on sale, and whether you can live with mass-produced/hand built or want them built-to-order. I got mine with the CD rims from Performance on sale for $241 delivered.