Emuviews

Great emulation page maintained by JoseQ, maker of the famous Rumor Mill, many downloads, great layout - some hosted sites.
http://www.emuviews.com/

Emula3

Contains emulators for many different computers and calculators/PDAs for many different platforms. [English/Italian]
http://www.emula3.com

Evenson Consulting Services' SWTPc 6800/6809 Emulator

Windows 9x/NT GUI emulation of SWTPc 6800 and 6809 systems. A Simulated Machine Environment (SME) emulation plus .dsk file downloads.
http://www.evenson-consulting.com/

KCemu

An open source emulator of the KC85 homecomputer series for Linux and Windows.
http://kcemu.sourceforge.net/

mic1

A Java-based simulator which implements the Mic-1 microarchitecture described in Chapter 4 of Andrew S. Tanenbaum, Structured Computer Organization, Fourth Edition. [Open source, GPL]
http://www.ontko.com/mic1/

Newbrain Emulator Pro

A freeware Grundy NewBrain emulator for Windows written in Delphi.
http://www.freewebs.com/newbrain/

blueMSX

An open source SVI318/328, MSX1, MSX2, MSX2+, and Turbo-R emulator for Windows.
http://www.bluemsx.com/

Japanese Computer Emulation Centre

A site dedicated to the emulation of Japanese Machines including X68000, PC6001, PC88, PC98, MSX 1/2/R, Sharp MZ, Sharp X1, Fujitsu FM7, and Fujitsu FM Towns.
http://www.jcec.co.uk/

TinyELF

A freeware emulator of CDP1802 based microcomputers for Mac OS X.
http://www.tinyelf.com/

vmips

An open source MIPS R3000 emulator for Unix.
http://www.dgate.org/vmips/