I'm torn between the 13" or the 15". I can see pros and cons of each. This will also be my first Mac computer. My last real experience with Mac was an Apple IIe when I was doing that whole K-12 school thing, so way outdated to say the least.
Personally, I have a pretty decent Windows PC that I use for gaming (What I'm posting on now) that's connected to a 24" widescreen monitor. I'm torn between screen sizes because of a few things:
13": I like the portability for when I do need to be on the go, I overall like the spacing between on the palm rest area and the general aesthetics, like lacking the speaker grill area and thinner on the sides. Screen resolution is kind of meh for me overall, but after looking at the Windows based laptops we sell where I work, the screen resolution was the same if not better than some of the larger screen counterparts. A plus for it is I can just hook it up to my 24" widescreen if I really want a bigger screen while at home.
15": I absolutely love the extra screen space. A bit heavier, but still lighter than what I was looking at with a windows based alternative. My on-the-go needs change quite a bit, sometimes I'll do roadtrips almost every week and sometimes I won't do that for a few months, so the increased portability of the 13" over the 15" is on the fence for me. The extra money spent on a 15" macbook with nearly identical specs as the higher end 13" I was looking at is almost not worth it to me, as I won't be getting the 15" with the better nVidia graphics card.
So overall, I think I have myself talked into a base higher-end MBP 13", and I might just upgrade to a faster/larger hard drive later on. My main concern is that I'm pretty indecisive and I don't want to not absolutely love the choice I make, as the amount of money spent will be considerable, at least for me.
Okay, I'll end my rant here, I was just really bored and reading through the forums and figured I'd make a random and useless post.
TLDR version: I'm not sure if I want a 13" or a 15" but I think I talked myself into a 13" and this is my first mac computer after using Windows based PCs for a long time.