There are some do it yourself liners out there that are garbage. Like walkercreek said, the slick liners are worthless. As stated, take care of rust issues before you ever put a liner in. Take care of both sides of the metal too, not just the interior. As for what is the best, it is a realitive term. I have used Rhino, Line-X & a couple of DIY liners. For cost effectiveness, Herculiner is the best. For just plain durability and thickness, I like Line-X better than Rhino for a couple of reasons. First it is cheaper than Rhino and second on the vehicles that I have used it in a similar fashion, it has stood up better than the Rhino has...for me. Now the trucks that I have those liners in are both work trucks, so they see a ton of abuse. As for the Herculiner, I sprayed it on the tub of my EB & my sister's CJ-5. It isn't as thick as a professional liner, nor as non-abrasive, but for the price, you can't beat it. It is tough, but very rough textured. My tub has 8 years on it and the only problem spot I have is under my heel where I wore through, but I have since re-sprayed the driver pan and sprayed it thicker and it matched into the old liner perfectly. I would recommend spraying it over rolling or painting it. Looks and feels 100x better. For the price you will pay for the professional job, you can buy 2 gallons, a compressor & the gun to spray Herculiner in. IF you use 2 gallons of Herculiner, you will roughly get about 3/4 the thickness of a professional job, but it will take longer because you have to let Herculiner set up in between heavy coats or it will sag.