Mountain bike racing, endurance races and cyclocross all seem more "welcoming" to women.
Road racing and TDF, in particular... not so good. Not sure about RAAM. I read "Hell on Two Wheels" recently and it didn't paint a rosy picture, in terms of the solo women's race.
Then again, I got turned off by TDF and road racing a long time ago anyway due to all the doping... I have no idea how much doping happens with top women riders compared to top male riders. I find the yearly Tour Divide mountain bike race much more compelling than TDF.

I don't race, but I think I should take some time to keep track of local women's races and cheer them on.