I would have to reccomend the neuspeed supercharger kit. warranty, easy to install, reliable eaton/roots type blower. will give similar perf to 150 hp 1.8 but delivered in a more city friendly manner(no lag) hope you have a manual trans dont know how fun the auto would be but anythings better than a stock 2.0.
the neuspeen sc kit gie you 50% increase which is to be exact 172.5 (had calculator near me
) but yeah, ive been in a jetta that had one, it is REALLY nice and a big kick in the pants. i recomend it, im gonna get one when i get the cash. i also have an exaust and intake and stuff so that will help it feel peppier. but yeah, just do the little normal things first and if ya want to spend the 3 grand on the s/c. go for it!