There are only 3 hard drive manufacturers left in the world: WD, Seagate, Toshiba. They own a few brands that they merged with but fundamentally only 3 manufacturers. No off brand left.
Reliability wise like mazdamonkey said, infant mortality of 1-2 years, just enough design life of 5 years, or over engineered last forever. Some generations of certain brand do better than the others in the same generation, because they made break through with some improvement (i.e. read heads that let them not fly as low, media that easily handle higher density), or screwed up the design that they cannot fix. The only way to tell is either user review after some time (newegg) or OEM qualification test.
I'm still using a Seagate 7200.7 in my PC for photo storage, it was made in 2003, and it is one of the most reliable drive ever made, although only 120GB. Laptop drive has much less mass so it is a lot more sensitive to shock, stay with 3.5" if you can and want reliability.
SSD these days have a lot less data retention than HDD if you plan to turn it off most of the time (design is 1 year with no power on at most), I'd not use it for cold storage. Most SSD problem is bad chips (drive manufacturers do not know how to screen out bad blocks, or buy cheap low quality chips from manufacturers, or did not have good relationship with vendor and couldn't get the top quality chips), or bad design (firmware bug).