Key prefixes of standard sObjects in Salesforce

List of key prefixes of standard sObjects in Salesforce is given below, I have covered almost all standard sObjects key prefixes, I hope this will help you.

Object prefix (Key prefix)	Object Type
001	Account
00r	Account Share
04m	Additional Directory Number
01p	Apex Class
07L	Apex Debug Log
707	Apex job
01q	Apex Trigger
806	Approval
04i	Approval Request
ka0,KA0	Article
02i	Asset
00P	Attachment
01m	Business Hours
019	Business process
04v	Call Center
701	Campaign
00v	Campaign Member
01Y	Campaign Member Status
08s	Campaign Share
500	Case
00a	Case Comment
01n	Case Share
010	Case Solution
02o	Category Data
02n	Category Node
0F9	Chatter Group
0FB	Chatter Group Member
09a	Community
003	Contact
00K,02Z,03j,02a	Contact Role
03s	Contact Share
068,069	Content
800	Contract
00b	Custom Button or Link
01N	Custom S-Control
015	Document
05X	Document Entity Map
091	Email Service
093	Email Services Address
018	Email Status
00X	Email Template
0E8	Entity Subscription
00U	Event
020	Event Attendee
0D7	Feed Comment
0F7	Feed Post
0D6	Feed Tracked Change
022	Fiscal Year Settings
00l	Folder
608	Forecast Share
00G	Group
011	Group Member
0C0	Holiday
087	Idea
00a	Idea Comment
kA#	Knowledge Article
ka#	Knowledge Article Version
00Q	Lead
01o	Lead Share
016	Letter Head
01H	Mail merge Template
0D5	News Feed
002	Note
006	Opportunity
008	Opportunity History
00k	Opportunity Product
00t	Opportunity Share
00J	Opportunity Competitor
00D	Organization
0D2	Org Wide Email Address
00l	Partner
026	Period
01s	Price book2
01u	Price book Entry
04g	Process Instance
04h	Process Instance Step
01t	Product
00e	Profile
03g	Queue Sobject
012	Record Type
00E	User Role
08e	Scheduled Job
0DM	Site
501	Solution
081	Static Resource
00T	Task
005	User
100	User License
03u	User Preference
0D5	User Profile Feed
099	Visual force component
066	Visual force Page
083	Vote

References
http://www.us-techpro.com/2012/06/key-prefixes-of-standard-objects-in.html
Force.com IDE schema