If you dont have it already, get the Canon 50mm f1.4. Its a AWESOME lens and is extremely sharp. This is honestly the best bang for buck lens. If you read the reviews for this lens, you'll see just how much everyone loves it.
And considering this lens can be had for less then $100, i dont see a reason why someone wouldn't get it.
2008 Lotus Exige S240 | 2007 BMW 335i