I have so many games but I get bored of most of them

Hook your PC up to your tv and plug your controller into it. Problem solved.

I dont get bored.
I feel sorry for you

The most time consuming PC games are MMOs if you aren't into any of those, then lately yes, most pc coming out are kinda short games(which doesn't make the experience of playing them worse or bad, like Bioshock).
There are some exceptions that will either be really way too long due optional things/quests, or extremely repeatable in different ways, but no game becomes boring if you have your friends playing with you. I can play anything on pc with friends or not. Consoles are really only for exclusives, GTAV ? i'll wait for the pc version thanks.

I don't get bored of games, but I have problems with indecision ... I have so much to play, I can't decide WHAT I should play at any given time!

How is this a problem? You can't force yourself to play. It is actually good, take up a new hobby like running or a simple body workout. You will be soon wanting time for playing and behind the computer once you create some time apart from it.

Size of library over the systems? A bigger library leads to more indecision about what you could play, and you become less likely to finish games.

I have the same problem with the small difference that I dont own a console and I dont spend hours playing on it, I just spend hours choosing a game to play and end up being bored the whole day

Same here. But I must admit that the COD games just seem better for consoles. You just have to find "that game". For me the only games I like out of the 62 (I think) games I have is only 2; which is Left 4 Dead 2 and Mafia II.

Maybe you associate your XBox with games, so when you start it up, you'll stay playing games. If you do a lot of other things on your computer besides play games, maybe you'll be tempted to do those other things while you're playing because it reminds you of other things. You might be in the middle of a game that you'd enjoy, but in the back of your mind, you're thinking about YouTube or Reddit or whatever.

I have the opposite problem. I extend my playing time and just fiddle around inside games much longer than it would take to beat them. It's not only trying to 100% them, but exploring and walking and talking repeatedly.

Tzell is having a similar problem in his own thread, you might want to seek answers to a NOGAEMEZ syndrome together.

For me it's the problem that I have less free time now that I work, go to school (high school), and do some college. I can't bring myself to starting Morrowind (Been fantasizing about it for weeks) just to play an hour and can't play for another couple days, so I tend to play things I can beat in a sitting or two (1-4 hours). I also have indecision, but not as much now since I have to really want to play somethign to skip homework for it XD The reason we are so indecisive is because we get SO many games, I get at least 5 new games a month just from bundles, so I always have something new I want to try.