Glossy, I was all about matte for a while but it looks like the glossy are better (they better be since I ordered an MB instead of an MBP). I like them because they look better. They seem brighter. I also have read from several people who have used matte MBPs and glossy MBs that glossy is actually easier to see in the sun. If you haven't already you should just go to the Apple store and spend a while on each one.
I prefer the Glossy displays. I've had both a Matte and Glossy MBP and I've stuck with the Glossy. Blacks are very very black and colours are more saturated and the display looks a little bit sharper to my eyes. However, the Matte displays just do not reflect light at all, and as such are perfect for places where you might have a lot of bright light sources shining onto the display.
I actually find the Glossy very usuable, even in places I thought the gloss would make it difficult to use. Your call of course, but for a portable, I'd go for glossy.
glossy makes the color pop out more, but i like my matte mbp because i feel like a glossy display takes away from its style. either way you cant go wrong, its been said if you are going to do anything with photos matte is better because the color is more true to life