Help choosing a new HDTV?

#$%& it! I’m giving in and gonna buy a new TV. I was doing fine but the TV in our family room broke the other day and I brought up another one (circa 1995) but can’t get any of the universal remotes to work on it. So… I want to buy one of these 42” thin screen TV’s but frankly I have no patience for learning all the terminology and sales jargon. I was at Target the other day and am pretty sure I want a 42 incher. Questions are:

1. there’s some sort of DPI number on the TV’s 720 or 1020 or something like that. Important? Rather not hear a discourse on screen resolutions/sizes—just bottom line it for me if you don’t mind
2. Are all these thin screens HDTV now? If not, how important is that? Do I have to buy a premium cable service to get the most out of it?
3. maybe I’ll want to play videos off my computer on the TV. Does that require a special TV?
4. So, which make/model should I get? I’m not a videophile but I want a nice crisp, clear, vibrant image.

What is the best value for a 42” TV and where should I buy it?

Thank you!