1 22" or 2 - 17" monitors

What do you do with your Computer?

If gaming, 1 22" is better.
If you do office productivity, then (2) 17" is likely better.

In a similar situation, I chose (2) 19" monitors over a much larger single monitor.

I love having (2) full screen sessions running.
Great for referencing one while using the other.

If you have a very strong video card, you will be able to play your games at Higher Resolutions and perhaps see more at one point in time which could be a gaming advantage.

The (2) monitor advantage for a game could be if you are doing some type of role-playing game that has lots of on-line Wikis for various quests.
Keep the Game running on one screen and the Wiki in the other screen for quick reference.

You may want to make sure your 17" monitors can handle at least 1280x1024 and not just 1024x768. 1280x1024 should be very sufficient for gaming.