I was in the same boat you are in. It's tough to find a 27" that will fit in these cabinets.
You have to keep in mind TWO requirements...
1. Fits in a cab that is around 25.25" wide
2. Has S-video
This is key because I found a lot of TVs that will fit on craigslist, but they didn't have S-video.
I found a lot of tvs with S-video, but they didn't fit.
I just decided to go to Walmart and get a new 24" flat screen. Honestly, it looks great and I don't notice the 3" difference.
Actually, 24 is almost to big as is.
Check out the photo with the 24"...