If money was no object, I'd say get a MacBook. I have one and I absolutely love it. Even more than my Toshiba tablet PC. Their primary fault is that they're expensive as hell. I paid around $2500 for mine. Granted it was custom-built, but you get the picture. You walk into the Apple store and a basic model is somewhere in the $1000-1500 range.
However, since you're on a budget, Toshiba is your next best bet. See if you can find something in the Satellite line, or if you need a tablet, the Portege line. Toshibas are sturdy, reliable, made with good-quality parts, and typically reasonably priced.
Third option would be, believe it or not, a Dell. Laptops are the only thing Dell does properly, but they do a decent job with them, and they're more modestly priced than a Toshiba.
Avoid Windows Vista on a laptop, try to get one with Windows 7. 7 has all manner of power management options... some optional, some built into the software. Laptops run longer with Windows 7.
Is there a Mac version of Star Trek Online? It'll play nicely on a MacBook/MacBook Pro?