As a Computer technician, this is quite a common question i’m asked. Some good hardware sites to check out are Anandtech, Xbitlabs, Legion Hardware and Tomshardware.
If you’re looking to spend upto $200 US, i presume you’re looking for a high quality Board (Abit/Asus/Gigabyte).
As previously mentioned, the Gigabyte GA-965P-DS3 or S3 (cheaper, doesn’t have the solid capacitors, no big deal) is a well tried and proven board. Make sure to get revision 3.3 (latest) for FSB1333 support for future CPUs.
Another great board at an excellent price is the Asus P5N-E SLI. Based on the new Nvidia Nforce 600 series (650i) this has pretty much unmatched features and performance for the price., and as the name suggests, SLI
This is an excellent guide to buying a motherboard, though it may not have the very latest, as is a constant work in progress:
Try looking at Newegg.com for prices (they’re generally the lowest or close to it) and user reviews. Keep in mind a lot of users’ reviews are from those not so technically competent even though they list their understanding as ‘high’.