I did not want to drill holes in the bed of my truck and I wanted something that I could remove if I needed the bed space. I've got the Delta Stable Loader with their Wheel Hitch System. I have been using it over three years and I am thoughly satisfied after making a small alteration. The rack bar has rubber padded ends, and no amount of adjusting the bar will keep them from sliding on my bed liner. I got a couple of small turnbuckles, threaded eye bolts, and S-clamps and used them to secure the bar to the bed tie downs. The bar now holds nice and tight, and is still really simple to remove and put back in. Unfortunately Nashbar makes you purchase the bar and the bike clamps separately.
I have a quick release rack (just the piece you hook the forks to) mounted on the inside of my tailgate, so the bike faces backwards. Makes loading/unloading a snap as I don't have to climb up in the truck. Was $15 used on eBay. A little loctitle and its not going anywhere.