Each to their own but we really enjoyed:
- Catania (gritty and real and authentic. Awesome fish market and an amazing pizza joint)
- Palermo was wonderful, particularly the old town. Make sure you head up to Monreale.
- we hired a car to drive across the island to valley of the temples near Agrigento, which is, we'll, a valley of temples. But great at sunset.
- head to Modica for chocolate and impossibly winding streets. Make sure you have a GPS if you are driving, and Ragusa on a Sunday night when everyone comes out to stroll.
- we also explored some wonderful villages on the slopes of mount Etna by hiring a car from Catania airport. Lots of good walking around here.
- Taomina wasn't our thing, but each to their own.
If you've only got 8 days, id suggest you focus on the area between Modica and Catania.
Some photos here: http://www.flickr.com/photos/simonmonk/sets/72157631917321772/ about 5 years ago