I know I'm just parroting along with everyone else, but in your case, a bike shop will be your best bet.

There's not a whole lot of difference in the top-end bike from Target (Forge Breva), and a base model Giant Cypress, maybe $40; but as you've seen, assembly quality on department store bikes is a roll of the dice. In case you didn't know, bikes are shipped partially assembled, and finished (and should be adjusted) at the store.

The LBS will (should) make sure everything is working right, and that you are on the right size bike, with the seat, stem, bars adjusted to the right fit for you. With a dept. store bike, you're on your own, or you bring it to the LBS for them to sort out, then negating the purchase savings on the less expensive bike.

What is comes down to is that you pay a little extra on the bike for the service and expertise provided by a dedicated bike shop.