My needs are simple. I need a shoulder type bag with a long enough strap to reach across my body to the opposite hip - lower if possible. I need a bag big enough to hold a book or more, and maybe my lunch and a water bottle. I need compartments and front pockets to keep things organized and keep my phone and keys and MetroCard available. (And to hold my wallet and pda and sunglasses, and a couple of other things that just live in my purse - this probably will include my notary stamp.) But I don't want it huge - I'm currently using an old Land's End Campus bag that's just too huge for my needs.
So, I went to http://www.timbuk2.com and created my own bag. I chose the medium sized one, with olive green on either side and black in the middle and a couple of extras and it looks really neat. I'll get it in eleven or so days.
I'm girly enough that getting a new purse excites me, but this is no girly bag. :)