I constantly miss SoftICE. Rasta Ring 0 Debugger was looking like a promising replacement for a while, but it just seemed to fizzle out and never got where it should've been. WinDbg isn't awful these days, but that's about the most praise I can give it.
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.
You can easily do that with radare2 already. As I mentioned already it does have WinDbg protocol support and is very portable by itself. Along with WinDbg it has support for GDB protocol. So you can run r2 on your Raspberry Pi and connect to WinDbg on your desktop and perform debugging from Raspberry Pi.
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.