There are various things I've gotten my mom for the past few years;
Modern Jazz CD's (Diana Krall... just basically anything that MrAngryFace likes)
Hand lotion dispenser (a nice clear green tint glass one was only 4 bucks)
Gift Certificate to Pier 9 (basically like Bed Bath and Beyond)
Female clothing you can't fuck up/don't really need sizes for (scarves, gloves, etc)
I dunno, it kind of depends on what your mom likes. But root through her music collection, I'm sure you could find some CD's or maybe even DVD's of artists she likes that she doesn't own.