If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears.
You can use "Disable all add-ons" on the Troubleshoot Firefox issues using Safe Mode start window to disable all extensions.
You have to close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")
Thanks for the help! When I start in safe mode, I get less crashes than I do in regular mode... I have 167tabs open and 1.6gb of memory in use by firefox. Is crashing because it is unable to allocate pagefile/memory space?