I'm also in the computer notebook market for a girlfriend.
So far, my research suggests that $2,000 is high. Given the short (arguably 3 year) lifespan of a laptop, you might be better off not to buy too extravagantly. Something to consider, anyway, depending on her budget. You might be able to get the ideal computer for her in the $1,500 range.
What I think is very important is to show her a big array of notebooks in any big computer store, and to ask her if she would prefer 17", 15", or 14". Don't bother her with the details; just let her walk by the computers and tell you which size she likes best. Once she has chosen, then you can consider weight, room on the desk or in the backpack, and battery life. If they look OK, then stay with her preferred size.
You say Vista "of course", but XP or even an Apple might be wiser choices. However, you are right anyway, as Vista is pretty well mandatory now, as Bill Gates controls a few hundred million of us obedient peasants.
I do recommend maximum
RAM, which might mean an upgrade to
2 gigs at the time you purchase the computer. In a short time the additional RAM will turn out to be a wise investment. Even so, be aware that a big chain store might charge you 2 or 3 times as much as the RAM is worth, and you might be better to look to a small, no-hype, non-chain, "real" computer store for that extra gig.
That's as far as I've got so far. At this time (and subject to change in a few months) Intel Core 2 Duo has the edge; but keep in mind that Intel Core Duo (without the 2) is a lesser beast. In between them, some folks say, is AMD's beautiful Turion. My own personal choice is the
AMD Turion™ 64 X2 Dual-Core Model TL-60, which rates a bit under the Intel competition.
I haven't made much progress on brands. I doubt that there are any truly bad ones left on the market. I do hear good things about some
hp and some
Dell notebooks.
Acer (not to be confused with Asus) is very controversial, called down by some people and praised by others; whatever the truth might be,
Acer is the only well-known name which manufactures its own computers —all those Toshibas, Dells, and everything else
are made by manufacturers most people have never heard of.
Work in progress. Hope that assists a little. Good hunting!