Pros: Pretty quick, cheap price
Cons: Can get a bit hot, failed once (the one inside my external drive)
The bottom line: 500GB for the right price, and good performance to boot.
With 500GB hard drives still the sweet spot for the best price/size ratio, it's been a very long time since hard drive prices had any dramatic changes in price. So with that, I went ahead and did a quick search around and decided to purchase from a reputable store.

So, it was natural for me to start searching for a 500 GB hard drive at NewEgg. I was pleasantly surprised that they are now around $100. The Western Digital Caviar SE16 WD5000AAKS 500GB hard drive was the cheapest at $95, so I decided to pick it up.

Specifications
Brand Western Digital
Series Caviar SE16
Model WD5000AAKS
Interface SATA-II 3.0Gb/s
Capacity 500GB
RPM 7200 RPM
Cache 16MB
Average Seek Time 8.9ms
Average Write Time 10.9ms
Average Latency 4.2ms

Package
There isn't really much of a package to speak of, since it was an OEM drive. OEM stands for "Original Equipment Manufacturer", which really means it was meant to be sold to someone who doesn't really need fancy packaging for the purpose of integrating it into devices (such as a PC). This means it doesn't come with anything but the drive itself. Coming from NewEgg, it was packaged well with plastic holders on each end of the drive inside of a box. The box in which a the hard drive is in is enclosed inside another larger box full of packing peanuts.

Because of this, you will not find cables, instructions, or even a warranty card. Don't worry about the warranty, however, as even OEM drives are warranted for 3 years. It's a far cry from the old 1 year warranty, but 2 years short of some of the best 5 year warranty Seagate offers. If you don't a have a reciept, Western Digital goes by the manufactuered date on the hard drive's label.

Installation and Use
Each computer case is different, and installation instructions differ from each case design. However, installing the WD5000AAKS is just like any other 3.5" hard drive. Since even the screws aren't included in an OEM drive, you would have to find your own. If you work with computers a lot, you'd have some lying around. Or you can always see if your local Best Buy Geek Squad or a local computer shop if they have a few they can give you.

It is a SATA drive, so you'll also need a SATA cable. You'd also need a power supply that have a SATA power connector, since the WD5000AAKS does not use a standard molex power connector.

I installed it as a second drive just for data, so I was not able to test Windows boot up and shut down. However, strictly as a data drive, I was able to test read and write performance. A maximum of 58 MB/sec read was reported via HDTach 3.0, while the average was around an impressive 52 MB/sec. Write speeds seem to be a tad lower at around 48 MB/sec. Microsoft Windows Vista seems to report similar numbers during transfers as well.

As far as noise level, it is very quiet. During access, you can still hear it if you have the drive outside, but inside of a computer case, it is near silent. The stock heat sink and fan for the Intel Core 2 Duos are silent as well, so it seems that any case would mask the noise of both the Intel fan, a large 120 mm PSU fan, and the Western Digital hard drive. You can make out hard drive access activity when you are about an inch away from the machine, and only if the room is void of any noise. This is due mostly in part to the fluid bearings the hard drive uses, as well as less movement of the heads now that data density is tighter.

The WD5000AAKS does feel warm after 8 hours of idling. During heavy access, it gets a bit hot. I can still leave my hand on it without it hurting or burning myself. However a little bit of air flow will help the longevity as well as the overal temperature inside the case. There does seem to be a bit of vibration, though - a little more than I am used to on other hard drives.

Conclusion
with Western Digital as one of the popular manufacturer, it's hard NOT to recommend any of their hard drives. There aren't many hard drive manufacturer I can't recommend as most of them are big brands anyways (Seagate, Maxtor, Toshiba, Hitachi, etc). However, a few that most people never heard of that may make their way into a store shelf. Most of them are long gone now, and their names forgotten. However, if it's not a huge name, don't buy it!

The Western Digital Caviar SE16 (WD5000AAKS) is an excellent drive for the money. Performance was very good for a 7200 RPM drive, thanks in part to the use of perpendicular recording technology. The 16 MB of cache also helps with small file transfers as well.

While there are other hard drives with similar specs I would recommend (as long as they are a large name and have a good warranty), I can only review what I own, and the Western Digital Caviar SE16 model WD5000AAKS is an excellent buy for me.

Update
I just realize that this is the same hard drive found inside my external hard drive! I am using this external hard drive for 6 months straight to store videos, music, and pictures for my Windows Vista Media Center. It was replaced once under warranty a month after I purchased it, but the replacement drive is running constantly for the last 5 months non-stop to feed my Media Center. Longevity seems pretty good (for now).

Hopefully, the same internal drive will be just as reliable inside of my desktop computer.