I bought my TV at Sears with the 18 month no interest deal. If I could go back in time, I would have waited a few months, and saved a couple of hundred bucks, but I couldn't take the constant crackling my 23 year old TV was doing due to a defective volume control (potted into a front panel module), and the replacement for it (found it online!) was almost what a decent new 27" CRT TV goes for, so I passed. Sear's price was what all the other local stores had on it, and almost exactly what One Call and several online vendors wanted anyway.
I make as large as possible payments on it every month. Last month, I didn't have to make any payment, but I gave them $150 anyway. I only owe $800 on the total bill now (I bought a drill press and BIG cordless drill too), and should have it paid off by the 12 month or so mark.
I got a similar deal from Dell when I bought my laptop from them a year and a half ago. An insurance check paid for almost all of it, and it was paid off in 9 months.