Well, not one of you that replied actually owns a Civic Si lol...does that say anything about the car itself? Actually been doing quite a bit of research and while the Civic Si is probably lags behind the cars mentioned above in value/performance, its pretty negligible and the cars turn out to be of similar price.
A SE-R with a moonroof turnsout to be around 19k, but its got 17's, foglights, a spoiler, and foglights.
The Mazdaspeed Protege is about 20.5k, but if you count that it has a 450Mw Kenwood Mp3 system the value is comparable to the other cars.
The Tiburon comes in around 20k, but it too comes with foglights, spoiler, and 17's.
The Honda has the least hp and torque, smallest rims, but I've heard that the quality and interior are top notch. Also, its likely to be the most reliable and will have the best resale value in 36 and 60 months from the AIG.
And we did go to the Nissan and Honda dealers today actually, seems like the Honda guys were really willing to bargain. My bro test drove it and the salesman was really indicating we could get a good deal, esp. since Honda is offering 1.9% short term financing. I think that with some bargaining one could walk away with a new Si for under 17.5k easily. As somone pointed out, I doubt you'd be able to negotiate such a deal with other dealers. The Nissan dealer didn't seem to think we could buy the car even though we drove up in our mom's 98 A4!