Acer are OK, but they're not the best brand out there. I bought an Acer laptop in 2007 (primarily because it was the only one I could find with XP rather than Vista) and replaced it last year because the keys were falling off the keyboard and couldn't be put back.
The build quality on my new Toshiba laptop and the Asus netbook seems much better. Someone did a laptop reliability study a year or so back and AFAIR Asus, Toshiba and Apple were in the top three slots (not necessarily in that order).