I am having a hard time deciding if I should purchase any of the following cards: Geforce gtx 280, 260 or 9800Gx2. I currently have a geforce 8800gt and want to ask the question, do you think its worth me upgrading? Will i see a much BETTER performance in games, like FPS etc...

I also have some other questions i would like to ask, so I may aswell put them to you here. I currently have a 32" LCD television that i use for my computer screen, it has a native resolution of 1366x768. What I was wondering is, could I increase this resolution beyond the native 1366x768 and if so will this damage the LCD in time. Thanks!http://www.nvidia.com/object/geforce_8800gt.html <-- what you have.
http://www.nvidia.com/object/geforce_9800gx2.html
http://www.nvidia.com/object/geforce_gtx_280.html
http://www.nvidia.com/object/geforce_gtx_260.html

Those are the Graphics Cards you've MENTIONED. (Click on the Specifications tab in the links)

The 9800 GX2 is pretty much a complete step up from your current graphics card.
It really depends on what you are going to do with the Graphics Card and what game's you will be playing.
You also have to take into account your computers specifications.

For example, a better graphics card may not mean better performance if your computer has low RAM and/or a low processor clock.

What kind of system do you have now and what games do you think you will be playing?

As for the LCD Monitor question, I'm not really sure here but I have had a widescreen monitor with a native resolution of 1440x900 running at 1280x720 for almost 2 years now, and it seems fine...Thanks for the reply, specs are listed below. I want to get a DECENT FPS for games like Crysis and MICROSOFT Flight Simulator x.

Motherboard: Ausus crosshair
Ram: 2GB Corsair
CPU: Amd 64 dual core 3.2Ghz
Hard drive: 250GB WD

If possible, more RAM would be nice but that's a pretty good system.

Your current graphics card should work well with Crysis (my friend has a weaker graphics card than yours and he can play Crysis pretty well on lowest settings.

But, I assume you want to play with the BEST graphics the game has to offer.