I have had quite an experience with racks!
I originally had the Yakima High Roller, and it was nice not having to take the front wheel off, but it never felt stable, and after reading a lot, I found out that wheel-on racks are not as secure as fork mount. So, after that rack was destroyed, I got the Yakima Copperhead, the basic level fork mount, and it was good, until it failed, and my bike flew off the car and onto the freeway. The construction quality of the Yakima products, at the time, seemed really great!
I've used friend's racks, most notably Kuat posted above, which is really, really, really nice, and probably the only one I'd consider for a hitch rack.
I recently went back to roof racks though, partially because WRX... can't put a hitch rack on a Subaru.
I am blown away... completely and utterly blown away by the quality and security of the Thule Paceline (http://www.thule.com/en-us/us/products/carriers-and-racks/bike-carriers/roof-mounted-bike-carriers/thule-paceline-527-_-1684640
). The way the fork mounts to it, the way it locks, the aero'ness of it, the little rubber things they put on the strap specifically for carbon wheels, it's like they thought of everything and made an amazing piece. I had hard time $400 for two of them, but I wouldn't hesitate to do it again in a heartbeat if I needed another rack. There's a dial you turn to adjust the skewer, then close the thing down and lock it together, after using it once I went "wait, why do ALL racks not work this way?".