The best papers are written about topics that the writer has dealt with first hand. So go outside and walk around your campus, go to the grocery store or pick up a newspaper. Look for conflict, and then look for underlying reasons for the conflict. Look at the way people interact with each other - are there "scripts" that people follow when they talk? Are there certain ways that people always behave? Look for these norms and explain why they might exist.
Of course there are tons of other possible topics. The best way to find topics is to look at different social groups (age, gender, race, SES, ethnicities, etc) and then explore how or why they are treated differently.
There's nothing quite like spending hours on a well written, well researched essay, only to receive a failing grade because it was off topic, so make sure you check that your topic fits with the assignment's requirements. Now you can start writing. Even if you are dealing with a topic you're directly familiar with, you still want to do some research. Look up articles related to your topic and write about how you see (or don't see) the research reflected in your personal experience. If you don't see it, discuss why you think the research doesn't apply to your situation. Writing a sociology paper doesn't have to be hard or boring. Writing about topics that you see every day will make your essay more interesting, more personal, and more likely to grab that A+.