Extracted from Windows Internals v5, pg 73 & 74
This is the most commonly used one's.  There is more discussion in the article "Inside the Native API" from Sysinternals.

This is for the stuff after the ! in the stack trace.

Variations:  
- The first letter of the prefix followed by an "i" (for internal) indicates an internal kernel function.
- The full prefix followed by a "p" (for private) indicates an internal process support function

Alpc - Advanced Local Inter-Process Communication
Cc - Common Cache
Cm - Configuration manager
Dbgk - Debugging Framework for User-Mode
Em - Errata Manager
Etx - Event Tracing for Windows
Ex - Executive Support Routines
FsRtl - File System Driver Run-Time Library
Hal - Hardware Abstraction Layer
Hvl - Hypervisor Library
Io - I/O Manager
Kd - Kernel Debugger
Ke - Kernel
Lsa - Local Security Authority
Mm - Memory Manager
Nt - NT System Services
Ob - Object Manager
Pf - Prefetcher
Po - Power Manager
Pp - PnP Manager
Ps - Process Support
Rtl - Run-Time Library
Se - Security
Tm - Transaction Manager
Vf - Verifier
Whea - Windows Hardware Error Architecture
Wmi - WIndows Management Instrumentation
Wdi - Windows Diagnostic Infrastructure
Zw - Mirror entry point for system services