HDMI vs. DVI vs. VGA

I have a 24 inch full 1080P HD external monitor that I am using with my Macbook Pro. I"m not really a gamer, so I have a question.

1st. What is the difference if I use the HDMI connection or the DVI connection to my monitor? Is there a difference?

HDMI and DVI use the same digital video signals, so should give the same image quality.

2.nd - what about just using VGA

It may not be as sharp as DVI or HDMI since the signal may not be sampled at exactly the correct pixel positions, and it cannot handle sharp vertical edges as well as digital.

Would the normal user, who isn't a gamer notice the difference in any of the 3 options?

A gamer is less likely to notice the difference because of fast moving images.

Also- I am only using this set up to have a bigger monitor. I'm not doing the extended desktop.

Unless you have a 1920 x 1200 display on the MacBook, you won't be able to use the full resolution of the 1080p display in mirroring mode, since it is a pixel-to-pixel mirroring. You can get full resolution by running with the MacBook closed if you use exteernal keyboard and mouse.
<http://support.apple.com/kb/HT3131>

Note: some 1080p (1920x1080) don't work properly with computers at 1920x1080. They may have overscan, which will blur the picture and put the menu bar and dock off the screen, or they may tell the computer to run in 1080i mode, which makes thin horizontal lines flicker. Sometimes this can be fixed with software, such as switchResX
<http://www.madrau.com/html/SRX/About.html>
or DisplayConfigX
<http://www.3dexpress.de/>

I don't think DVI passes audio signals. Remember also there are different types of DVI, (DVI-A, DVI-D & DVI-I).

The 15" MacBook display is 1440 by 900, so will not use the full resolution of a 1080p display in mirroring mode. Closed lid, or extended desktop can use full 1920 x 1200.

The only way to see if there will be any other problems with a 1080p TV used with a computer is to try it. Fortunately you have a laptop, so you can take it to the TV store to try it. If they won;t let you, find another store.

Just follow the instructions in:
<http://support.apple.com/kb/HT3131>