Samsung 830 and Crucial M4 are the most popular. Prices continue to drop and you can get a 128GB Samsung 830 for $100. 240GB for $210. I just bought an 830 and love it. It's the first SSD I've owned and I'll never use a standard HD again for the OS.
Tigerdirect has the 128GB for $90 after promo code.
Tom's Hardware usually has a "daily deals" article in the Latest News section on the home page. The daily deals are over at LogicBuy. LogicBuy also has a daily deals page just for drives. Here is the link: