Seagull, Fender and Yamaha and even Mitchell make excellent guitars in the introductory ranks. I know you didn't specify beginner but am assuming you are interested in guitars that are not super expensive but still worth your money.

I think the main thing would be to get a guitar that is comfortable to play and hold. This is different for each of us because our bodies are all unique, and you'll have to get out and play with a bunch to find a match.

In your search for a good acoustic I would want at least a solid top. Solid woods get better sounding as they age, and there are lots of solid top guitars to be had under $1000. All solid guitars are the better investment, but are more money out of the gate.

That being said, I have a Fender DG8S that I love, the CD140 series are great, and I have played Seagull Entourages that I enjoyed. The Yamaha FG720S (or any of the 700 series, really) is awesome, Mitchell MD or MO 100S are both good, and I really like the Breedlove concert size guitars. But the more I play "other" acoustics, the more I'm finding that I really enjoy playing the concert and auditorium sizes, which comes back to the right size and shape for you... Its like being a kid in a candy store :)