Completed "Reilly's Rangers" but Fallout 3 crashes when I go through the door to the Ranger Compound. I get a "black screen of death".

This seems to be the only location so far that causes the crash.

Playing on Windows 7, Steam version, no mods.

Crashing on one cell load can usually be sorted by going somewhere else and working on a different part of the quest or a different quest then come back. That has worked for me in the past.

Now, are you just going back for a visit, or are you turning in some map points to Reilly? If the latter, try going out and discovering a location or two, then go back and try again. Which leads into what I said in the first sentence.

I was trying to enter for the first time after completing the initial quest.