Besides gaining reputation with your questions and answers, you receive badges for being especially helpful. Badges appear on your profile page, flair, and your posts.

Question Badges

First bounty you manually awarded on another person's question
First bounty you manually awarded on your own question
Asked a well-received question on 5 separate days, and maintained a positive question record
15 awarded
First bounty you offered on another person's question
Question score of 10 or more
59 awarded
Asked a question with 1,000 views
4 awarded
First bounty you offered on your own question
Asked a question and accepted an answer
97 awarded
Asked first question with score of 1 or more
144 awarded
Asked a question with no votes, no answers, no comments, and low views for a week
4 awarded

Answer Badges

Answer score of 10 or more
72 awarded
Answered more than 30 days later as first answer scoring 2 or more
10 awarded
Answered your own question with score of 3 or more
13 awarded
Answered first question with score of 1 or more
164 awarded

Participation Badges

Completed all user profile fields
1.2k awarded
Left 10 comments
54 awarded
Earned at least 200 reputation (the daily maximum) in a single day
Followed the Area 51 proposal for this site before it entered the commitment phase
Posted 10 messages, with 1 or more starred, in chat

Tag Badges

You must have a total score of 100 in at least 20 non-community wiki answers to achieve this badge.
9 awarded

Moderation Badges

First flagged post
13 awarded
First rollback
6 awarded
First down vote
97 awarded
Completed at least one review task. This badge is awarded once per review type
4 awarded
Deleted own post with score of 3 or higher
3 awarded
First edit
100 awarded
Edited first post that was inactive for 6 months
2 awarded
First retag
27 awarded
Deleted own post with score of -3 or lower
3 awarded
Approved or rejected 100 suggested edits
Used 30 votes in a day
2 awarded
First up vote
558 awarded
First approved tag synonym
1 awarded
First tag wiki edit
2 awarded
Used the maximum 40 votes in a day
2 awarded

Other Badges

Visited every section of the FAQ (retired)
54 awarded
Shared a link to a question that was visited by 25 unique IP addresses
1 awarded