CAUTION : GO TO THESE SITES AT YOUR OWN RISK.. SOME OF THEM MIGHT CONTAIN PICTURES OR HUMOR WHICH SOME OF YOU MIGHT CONSIDER OFFENSIVE.
(Such sites have been clearly marked with a "!!!" sign..., the number of exclamation marks indicating the degree of offensiveness)  

YOU HAVE BEEN WARNED!!!!

That being said, most of these sites are not offensive.. They are excellent in the topics they deal with (most of which are of no practical use) , and you would be missing what the net is all about if you don't visit these sites. The net is full of people.. some of them are a bit weird.. Most of these pages have been made by people who are REALLY weird..

1) www.rotten.com : (!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)
(Rating : Even I hesitate to give this site a rating of any sort...)

The MOST offensive site on the internet. It has been variously referred to as " The stinking underbelly of the internet" and "The most useless site on the net" .
What does it contain? There is nothing sexually explicit, but what would you think of a site that contains a series of photos which are entitled "Railway accidents" ???

2) www.fosi.da.ru : (!!!!!)
( Rating : 4.5 / 5 )

The premier site for hacked Full Version computer programs on the internet.. If you are looking for a particular program and its popular (e.g if you want the full version of "getright" ) , you can be quite sure of a speedy and reliable download from this site.
Why the exclamation marks? Sadly, most of the revenue that the site earns is through banner ads , which wouldn't be bad were it not for the fact that most of them are of a pornographic nature...
Very good site if you disregard the ads.

3) www.crack.ru : (inoffensive)
( Rating : 4 / 5 ... )
Although the search engine is surprisingly comprehensive, applying the cracks themselves might not be everyone's cup of tea.

Do you have a trial program that you like very much but which is about to expire in a few days? Don't have money to buy the program? You could try searching for a crack of the program at this site.
For those of you who don't know what cracks are, here is a quick primer : Cracks are small programs which when run modify the shareware (trial ) programs that you are using so that they run indefinitely instead of stopping work in a month or whatever the trial period is.
Applying a crack is very simple.You just copy the crack file to the directory in which the shareware program is stored and double click on it twice. You only have to do it once.
BE SURE TO SPECIFY THE VERSION NUMBER OF YOUR PROGRAM WHEN YOU SEARCH FOR THE CRACK. 
(this can be found by pressing Help->About in the program window.)

4) www.astalavista.box.sk 
(Contributed by : Dr. Samir Pandya, ex- GScite )

This site is similar to the crack.ru site. However, you might find some cracks on this site that you wouldn't find on the crack.ru site and viceversa. This site is also quite good , although www.crack.ru still remains my favorite.