Get some pics up first of all
it all depends how much money you want to spend really..
-exterior styling
Smoked Headlights, De-slat the grill, de-wiper, lower it, new wheels
-interior styling
new speakers/tweeters/sub, Gti leathers,
-sound better
Mine only has a 4" Backbox and it sounds sweeet, but if you want that raspy noise then its best to get the full exhaust system. A supersprint system is very good quality i've been told
-lower
Apex kits are very good but for the best quality go for GAZ coilovers
-handle better
Coilovers/Shocks, Generally lowering the car 40mm for example will improve the handling but as most people will tell you a car with a uprated suspension set up will be able to piss all over a car with much more power but with a standard setup
-brakes
A standard Mintex disc, caliper and pad set can improve your brakes fairly well but there are many other kits to really upgrade them..
Hope that helps