It depends on how much need you have for a router...
If you're an avid woodworker who has a daily or at least weekly need for a router, then spend the money on a good one from a reputable manufacturer.
If you'll only need one occasionally, look at these two. The first is advertised as a trim router, but it would be suitable for small cavity holes and the like. The second is a full size router capable of doing just about any job you'd need a router for:
http://http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44914
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=37793
Harbor Freight Tools has been maligned by some as nothing but a source for cheap Chinese made tools, but seeing how many of the "name brand" tools are now sporting the "made in China" label themselves, I can't see why I should pay an inflated price when there's Harbor Freight.
I own one of the bigger ones pictured, and it's a real work horse. Plenty of power, torque, and it makes nice cuts. Will it last as long as a more expensive unit? Maybe not, but it certainly hasn't given any indication that it'll quit anytime soon. I've seen the trim router on sale as low as $14.99, and I bought the one I own on sale for $49.95 back a few years ago.
BTW: I own one of the Dremel rigs too. It's really handy for small trim work, but it lacks the size and power for large, deep cuts.