At the lower-end pricepoints...there's really not a big variance between build quality. Some companies might get you a little better bang for your buck, but in all honesty, think of them as more or less the same bike with different style. Ride as many as you can, pick the one that fits you best. If you don't like being on the bike, you won't want to ride it, and you'll lose interest in the sport and will end up regretting spending all that money on a bike you don't ride. Ignore brands (most entry-level hardtails are actually made by either Giant or Pacific), ignore marketing, ignore colors, and go by feel.