I got a cheaper hobby drill with a big selection of bits on offer at Maplins but there's other good places to get them too.
I mainly use the largest drill bit that came with it, something like 3mm, but when I eventually get round to making my own PCBs I'll probably want to get a smaller drill bit for putting the holes in that. Been reading that tungsten carbide bits are better for that, but are fragile and expensive so a drill stand would come in very handy here, and save you money in the long run.
Also seeing regular use is an Abrasive Point bit, which I find handy for grinding down bits of case plastic that are getting in the way of mounting any pots/switches/etc.
And also the cutting discs can sometimes be handy if you want to cut a big chunk of plastic out of somewhere. Make sure you wear glasses/goggles when using these though - if you're unused to them and cutting at the wrong angle with too much pressure they can break while the drill is spinning, sending a few jagged shards flying into the air... you don't want that happening!
