From the moment I bought my Rabbit, I was smitten. The 2.5 liter engine growls a bit when you step on it (which i like), but otherwise is very quiet and responsive, even in 5th gear on the freeway. The seats are firm but comfy and the dash is laid out nicely. The red-on-violet instrument cluster is complemented nicely by the soft red interior lighting...quite sexy. I didn't think the one-tap lane-change feature was such a big deal until I used it. One tap and the turn signal blinks three times without having to hold it, nice. I whittled my original list of 12 cars down to 5 and then test drove them all. The Rabbit beat them all out in the price-to-value category, big time.
The red-on-violet instrument cluster, the 2.5 liter engine, the one-tap lane-change feature, the soft red nighttime interior lighting, the short throw gearbox, the interior and exterior lighting.
The only two things I can think of: add a CD player with a built-in equalizer and song time display, and perhaps give it a little racier (aka sexier) sheet metal.