This came up recently so I figured once again I'd make a post about it.
The factory did offer a set of tow hooks found standard on all "Up-Country" packages and some other models found in the older years.
Here is a photo of the stock (factory) setup. If your junk yard hunting you need ALL the parts shown below.
These are an "ok" option and work well for the occasional wheeler who does not wheel a lot. However they are not as strong as an aftermarket set. They have a tendancy to bend on a side pull as the metal just isn't "thick" enough. Do not in my opinion give more than $50 for a set of the factory one's with all hardware.
Another option is Rusty's tow hooks. Based on experience and from hearing a lot from others who've ran them; DO NOT BUY THEM. They do not have the side support bracket and WILL bend if you use them on a hard pull. You can spend your money as you please, however just don't say you were not warned by someone who's bent a set of them...
The popular (and best in my opinion) are the C4x4 brackets. They are very beefy and will not bend on side pull and can take the abuse you throw at them. I run them on all our rigs and have been very happy with them. They can be bought HERE for $85 for the set.
So in close, the best option in my opinon is the C4x4 one's at $85/set. Just make sure whatever set you go with you have all the bracketry and hardware (shown above) to mount them correctly. Do not think you can just go out and buy a $10 hook from TSC and bolt it to your bumper. IT IS NOT SAFE, and you'll have a hard time finding someone to yank on you if you do...
i run them on the Jeep. the first time i used them, i was stuck in a mud hole and had a 92 bronco pull me out. he pulled me out no problem. well i got out of the truck and the 1 hook was completely bent. so i had to bend it back and make a brace that went from 1 hook to the other. ive used them a lot after and haven't bent since