Capitalman, I have to respectfully disagree. The extended warranties, on anything - not just TV's, have the highest profit margins of anything a store sells, higher than their credit cards even. Generally speaking, if there is something wrong with the TV, there is a great chance it will show within the first 6 months, well within the warranty included. Note as well that while most companies include 1 yr warranties, some (all?) Samsung models offer 2 years. In terms of 'burn-in' on plasma's, all the warranties I saw (both factory and extended) are pretty explicit in that it is NOT covered.
Angela, There is much valuable advice in the above posts, I hope I can add to it. In terms of what to buy, I did a huge amount of research in purchasing a new TV for a family xmas gift (I can get kinda obsessive about these things!). I started thinking plasma, convinced myself that LCD was better, and then finally went back to plasma and I am very happy with my decision.
Two points:
1) In order to get the best tv for you, you have to be upfront and honest about your viewing habits. Do you use the tv for sports? movies? video games? regular channel viewing? Do you plan on subscribing to High Definition channels (yes, they cost extra)? Where will the tv be? Where will you be sitting when watching the tv? Do you like to keep the tv on 'as company' even when you're not really watching? Do you fall asleep in front of your tv? Ask the salesperson: "Should I get LCD or Plasma?" - if they give you an answer then find someone else. If they say "I can't answer that" and start asking questions about how you will use it, then they very well may know what they are talking about.
2) If you are going from a 13" tube to a flat-panel, ANYTHING is going to look amazing to you. It's like going from a beat-up Toyota to a Ferrari - you won't really care if it's a 550 Marinello, a Testarossa or a 612 Scaglietti... it's a FERRARI!
Hope this helps.