Softice
I really want to build a decent wrapper around the WinDbg protocol and run it on a Raspberry Pi+display that sits on top of my desktop case. That way I can just grab that and break in any time I need to debug something.
[1] https://www.botconf.eu/wp-content/uploads/2014/12/2014-2.1-W...
[2] https://github.com/radare/radare2/blob/master/doc/windbg