Branded frames make very little difference.

Branded components make a BIG difference. Shimano, you want to see components that have names on them, there are some bottom-of-the-barrel Shimano parts that are un-named, but even the lowest names (Acera, Alivio, Altus, Tiagra, Claris, maybe Tourney is a little iffy). SRAM is probably all good, Campagnolo doesn't make anything crap.

The biggest tell for me is, on a bike with V-brakes, look at the way the brake arms are constructed. Are they stamped from a thin flat piece of metal into a thin curved piece of metal, likely the whole bike is crap. If the brake arms are forged or cast as a more solid piece of metal, you're probably on safe ground with the whole bike.

And if you find a bike with reliable components, they'll almost certainly be on a frame that is good enough (assuming it FITS you and is the right style of frame for the kind of riding you want to do: road/drop-bar? fitness/hybrid/flat-bar? mountain/knobby tires?)