There is so much I could say here, but it's late and I've already started over like 5 times. So here's an unorganized smattering:
Straight women can be fun as long as you don't fall in love with them and as long as they don't fall in love with you. At least, I've found them fun.
My partner has a long history of falling for straight women. She likes feminine women. Most of them have been straight. I'm the first femme she's been with. Heaven forbid we ever break up, but if we did, I'm pretty sure she'd keep dating femmes rather than going back to straight girls. I think it's pretty heart-wrenching to spend your life falling for women who will always be more interested in another gender than your own.
On a totally different note - I have known some butches who tend to measure/validate their masculinity by defining their partners as "straight" whether or not they actually are. As though straight women being interested in them gives them some sort of cachet. When I first came out, I dated a butch (briefly) who would have preferred to define me as straight in order to serve her own ego. It's hard to explain, but I've run into that attitude plenty.