MavRom 2.0. Plus it has a really cool ICS theme.
Right now I'm running
[SELFKANG ICS AOSP ROM] CM9/ICS for Droid 3
and it is sweet! Apparently it's still in stage 2 of alpha but I'm literally seeing a super stable ROM here. Literally the only crashes I get are occasionally from the launcher and I have not had one reboot.
All the ROM's are necessary, and all good in their own right. It is a shame that the device does not come stock with something like the Maverick 3.0 ROM, with even less bloat. The D3 is a really capable device, and with the stock software was a constant source of frustration. I tried the VZ support route and after many hours of support calls and frustration still had a device which rebooted multiple times per day, crashed constantly and needed a charge by midday. With the Mav Rom's and some de-bloating, I easily get a full day per charge and no reboots or FC's. Actually been up for 7 days straight on MAV v3, a record for me with this device.
Even using the camera does not crash Android! (it is a shame this is a big deal). I used to recommend Android all the time, but after my D3 experience I will only recommend Android to semi-technical people willing to root and fix the issues themselves. Most users are better off with a closed device like Windows Phone or Apple, if they are not willing to get a stock android device like a nexus. (which I understand has bloatware installed as well).
I don't see why VZ/Moto would not just recommend app's in the market, seems like it would be a better approach and actually reduce service issues. The manufacturers could distinguish themselves with add-on options like launchers and widgets and hardware specific software (camera's keyboard, audio) - while building the devices optimized for AOSP code for basic functions (like dialer, gmail, browser).
Mav v3 is clean and close to stock, and has some great themes which are all visually interesting. I highly recommend Mav v3.
Tried most of them but my favs so far
1a Eclipse 2.2.1
1b Mav 3.5
2 Team Gummy ICS (dont know the actual name of the ROM)
3 MIUI ICS
Stock Rooted HTC Rezound