I have a 14.4 DeWalt. It's just a bit more than I need for around-the-house use. If you read Steve:'s Follow-up already, you'll see that 'between the lines', he's answering your question based on HOW you use the drill. I can't think of a reason why you'd want a 18v drill for around-the-house use. I think a 14.4v with 2 batteries is plenty. And as Steve: said, 12.2v serves his purposes just fine. So look at you're gonna use the drill and go from there.
As for branding, I think all 3 are good ones. The bells-and-whistles might be worth comparing. Look at battery-replacement costs too. Yes, I'm sure there will be more opinions.