Sigma DG 52mm Multi-Coated UV Filter
Sigma offers a nice UV protection filter option that still includes multiple coatings but doesn't break the bank. This filter is designed to stay on the lens at all times, and can even be used in conjunction with other filters. The glass itself keeps out dust, moisture and other lens hazards, while the coatings keep out unwanted glare. The filter screws on and off easily, though you won't need to take it off much.