Shocks are the single most important component of a suspension IMO. They have the greatest effect on ride quality over any other piece as well. It's all give and take though. Shocks dampen your springs through their travel, while the springs basically just hold the car up and prevent it from bottoming out. Shocks are your primary contributor to how a car handles, rides, and transfers weight.
I think generally it's easy to get a set of shocks that ride good on the street, and are also suited for one other purpose (handling vs. weight transfer). Here is what I think...
Budget Drag Racer: KYB AGX
Best Choice Drag Racer: HAL QA1
Budget Handling: Bilstein Revalves
Best Choice Handling: Koni Single Adjustables
*I've had stock shocks, Bilsteins, QA1s, and now Koni SAs on the car over the time I've had it. I've spent alot of time trying to get my suspension just right, and I'm finally happy with the way the car rides, handles, and even performs at the drag strip. I'm running Koni SAs. They are the best all around shock on the market, by a LONG shot IMO. You pay a little extra, but shocks are the most critical part of your supsension IMO, so it's worth it. My car on stock springs and Koni SAs rides very nicely (better than stock), transfers weight fairly well at the track, and handles great. They are a little harder to adjust but the range in which you can set your car up to perform any given task (street driving, drag racing, autocross) is priceless IMO.
