Currently my preference is with WD, mainly for price and warranty reasons (they're cheaper and have 5 years warranty here, vs 3 years for Seagate.) Mainly amassing WD Greens for huge amounts of storage. Drive speed isn't an issue because they're all going into an NAS which feeds the home network at gigabit speed only, anyway.
After a couple of months with an SSD (Intel X25-M G2) I think I'm going to find it hard to go back to mechanical drives for the OS partition...

Ignore the specified boot time of 30:12 (bootchart oddly doesn't display it as 00:12 and I don't know why), the chart clearly shows it as 12 seconds. That's after POST, up to login screen, and without any boot optimisations (yet).
For those who aren't gamers and won't need 80GB of space on the system partition, the Intel X25-V, OCZ Vertex and Kingston SSDNow V+ series are decent buys for SSDs 64GB and below. Of course, they won't be rubbing shoulders with the better SSDs, but you will definitely feel the difference compared to a mechanical hard disk. And all 3 come with TRIM support, too.