I could not find any topic about this, which was kinda surprising.
Brickset.com is a website that helps you keep track of the sets you have and the sets you want. According to Brickset, I own 265 individual sets, 282 if I count the sets I have more then one.
I have approximately 250 minifigures and around 21,000 LEGO parts (this is only an approximation, I also have a tone of spare parts I got, my total parts collection might be close to 25,000).
This site is very useful, I really recommend it to any LEGO fan.
What about you? Do you use this website? If so, how big is your LEGO collection according to it?