Generally, buying an off-brand HDTV is a bad idea unless you can see one up close. They often use cheap parts which cause the colors to look "off," the upscaling to be poor, or any number of other things.
Also, don't buy refurbished. They have a much higher failure rate than non-refurb.
If you really want a good HDTV in your price range, I'd go for specs over size. If you're considering something smaller, I wouldn't bother with 1080p, since they only come in 40"+ sizes, and that size upgrade will come with a pretty steep hike in price.
If your limit is $550, you should be able to get a quality 23"-26" Samsung or Sony for about that price with a little shopping around.
Things to look for:
1) At least 8ms response time. Anything more and you'll probably experience slight "ghosting" effects, but anything less you'll probably be overpaying for. (And, no, 8ms will not give you "ghosting." My 23" Samsung has 8ms response, and I've never experienced anything of the sort.)
2) A high contrast ratio. At least 3000:1 will give you the best results, and I wouldn't settle for anything less. The higher, the better. (So, in other words, 4000:1 is better than 3000:1).
3) Lots of inputs, especially if you're not hooking it up to a receiver (and with a 26" TV, I'd imagine you won't be.) I wouldn't settle for anything less than 2 HDMI and 2 component inputs.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom
