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
6 awarded
First bounty you manually awarded on your own question
28 awarded
Asked a well-received question on 5 separate days, and maintained a positive question record
41 awarded
First bounty you offered on another person's question
13 awarded
Question score of 10 or more
227 awarded
Asked a question with 1,000 views
98 awarded
First bounty you offered on your own question
45 awarded
Asked a question and accepted an answer
368 awarded
Asked first question with score of 1 or more
842 awarded
Asked a question with no votes, no answers, no comments, and low views for a week
24 awarded

Answer Badges

Answer score of 10 or more
173 awarded
Answered more than 30 days later as first answer scoring 2 or more
147 awarded
Answered your own question with score of 3 or more
19 awarded
Answered first question with score of 1 or more
502 awarded

Participation Badges

Completed all user profile fields
896 awarded
Visited an election during any phase of an active election and had enough reputation to cast a vote
Left 10 comments
111 awarded
Earned at least 200 reputation (the daily maximum) in a single day
11 awarded
Followed the Area 51 proposal for this site before it entered the commitment phase
36 awarded
One post with score of 2 on meta
72 awarded
Posted 10 messages, with 1 or more starred, in chat
31 awarded

Tag Badges

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

Moderation Badges

First flagged post
96 awarded
First rollback
9 awarded
First down vote
114 awarded
Completed at least one review task. This badge is awarded once per review type
178 awarded
Deleted own post with score of 3 or higher
2 awarded
First edit
514 awarded
Edited first post that was inactive for 6 months
23 awarded
First retag
36 awarded
Deleted own post with score of -3 or lower
14 awarded
Approved or rejected 100 suggested edits
3 awarded
Used 30 votes in a day
14 awarded
First up vote
1k awarded
First approved tag synonym
6 awarded
First tag wiki edit
11 awarded
Used the maximum 40 votes in a day
12 awarded

Other Badges

Visited every section of the FAQ (retired)
37 awarded
Shared a link to a question that was visited by 25 unique IP addresses
87 awarded
Read the entire about page
129 awarded