As of right now i think i know of like 6 different ways to end the game, im not sure if some of them will run into each other and be one.. but whatever
Just from meeting getting to the tops casino you get 3
-Work with Benny to take over vegas
-kill Benny and take over vegas (probably goes to helping Mr House)
-Talk to Yes-Man and take over vegas yourself
-Work with Mr House to take over vegas
- Take out Mr House for the NCR and work with them
- Work with Caesars legion to take over vegas (idk how many different choices you get from working with them, maybe you can kill Caesar and be the new leader? idk)

Im not sure if working with benny actually works because he seems like he would be a backstabber..

So im wondering how many different choices there actually are in the end. How many different ending are there? (I DONT WANT TO KNOW WHAT THE ENDINGS ARE)
like in fallout 3 i remember there being 3 or 4 different endings?

There are 27 different parts to the ending of the game. Upon completeion, listen to the narrator who tells you the result of each of those 27 parts. Each Part has between 4 and 13 different endings.

Things that were missing in the ending I did:

1) Veronica - they told me what happened to the other companions, but not her? I have played two different endings, and neither one told me what happened to her.
2) Caesar - He wasn't at the battle of Hoover Dam, just some Leggy guy. So what happened to Caesar? The ending didn't tell me.

Have you done Veronicas personal questline (all of it)?