I think Samsung is the best, overall, choice. Imho. The F3 and F4 EcoGreens are good for storage and receive good reviews. The Spinpoint line is good for an OS drive if you can't get a SSD.
I would pick a Samsung drive if available. As for other choices, the Seagate 7200.12 is the only Seagate I'd consider for an OS drive and the LP series is a satisfactory choice for a storage drive although a Samsung HDD is my preferred choice for that, too. However, in my area, Samsung drives are only available at newegg AFAIK and cost considerably more than same capacity drives. Therefore, I usually consider other makes even though they're not my first choice.
I think WD Greens are satisfactory choices based on price if you need a storage drive. I am considering a WD10EARS because of price.
The thing that I think is ignored is the temperature/power that the drive has and I think going for a lower power/temp drive is preferable, particularly, if it's going to be a storage drive.
The other drives that I think are good choices are Hitachi. i like Hitachi drives since they don't have all sorts of lines and models. I think they might have revisions or re-designs but usually it's only one or two that are current. Therefore, when you read one has failed or someone is displeased with them, it's because they are mass producing the same model or models and it's probably not very many different models. Naturally, a few bad ones will slip through the cracks.
I'm not sure about Seagate reliability. They might have improved QC but it still might not be at a level that one needs for hard drive reliability. It's pretty important to have QC when it's your data! I would only consider Seagate based on price and only certain models, maybe between two whether I need an OS drive or storage drive. Whereas, I'm more willing to consider several different models of Samsung drives, for e.g.
So, based on preference:
1) Samsung
2) Hitachi - note: most if not all are 7200rpm speed so more applicable as OS drive choices
3) WD - Greens for storage, Blues for OS (if price is lowest) and Blacks for OS (although, might run a bit hot/high power)
4) Seagate - 7200.12 for OS drive and LP series for storage
I generally compare and consider WD and Seagate drives usually but mostly based on price/cost reasons.