I can tell you the best thing I have ever done was order Turbo Jam. I've been exercising since I was in high school (I am 36 now) and I was doing Taebo for the last seven years. So I can't answer as far as the easy to pick up part since I was doing some kickboxing. It is different though but with the Learn & Burn, Chalene goes through the moves over and over that I think it would be easy to learn. Same with in her other workouts . . . I still make mistakes but as Chalene says "mistakes burn calories". Out of all my workouts that I have done from the Firm, to Cathe Friedrich, to Taebo, Denise Austin, Slim Series, Project You & Kathy Smith, etc. . . . This is by far the best and most fun - and the one I am reaching for every night I exercise.
I would FOR SURE order the first set, especially if this is new to you. It is cheaper in the long run and you can always sell the ones you don't like on ebay and make money. The only one I don't do as often of the first set is the Lower Body but I won't get rid of it. The Learn & Burn is a very important workout even though it is only 15 minutes. I still add it in every once in awhile. The 20 Minute is one of my favorite workouts. I also like Turbo Sculpt. Ab Jam is not bad and I do it - but ab workouts, even Turbo Jam's are not my favorite because I have a huge belly and it gets in the way . . . LOL
Chalene recommends ordering the sets as they come out and I know it's not because she wants people to buy them (although I know she does that too) - it's the intensity part of it too. I wouldn't have been able to do Cardio Party 3 if I hadn't learned Cardio Party 1 and 2 first. Some people don't like the Cardio Party's 1 & 2 - I do - they are great 40 minute workouts that burn 700 calories. Again, if you didn't like them, you can sell them and make your money back and probably some extra.
My new favorite is the Punch, Kick & Jam which is 50 minutes. I didn't think I would ever want to exercise for over 50 minutes ever again (I burnt myself on Cathe Friedrich exercising for 55 to 70 minutes 5-6 days a week for over a year) - it is a lot of fun and she has a longer stretching period at the end which I also like a lot.
No, you won't be able to get "results" with one video. You need the cardio and a sculpting one for sure.
I wouldn't be able to pick just one because I like them all for different reasons - it would be way too hard. I really would recommend buying the first set and going from there. You could do that and skip to the newest set much easier then buying say a Cardio Party 1 and doing that for the first time without ever doing a TJ video again. It might not be pretty.
Someone mentioned on the other post that they are selling for cheap on Ebay. My thought is that they might be copies but it's worth checking out.
Good luck! I hope you try TJ - it really was the best thing I ever could have done. Rachelle