Spineless Whelp, see also "pyre"

I really hate rejection, you know that?
Wait! Come back everybody, this isn't another lonely pathetic guy on the internet talking about how he can't get a date! Really, it's okay, you don't have to read yet another lame series of whining like that. There's too many of those online already. This is something different. Anyway, where was I? Oh yeah...

I can't get a date- NO! Just messing with you folks! Kidding, kidding.

Really now: Being rejected sucks, we can all agree on that. But being on the other end of rejection isn't fun either, I've learned. Yeah, one time before I had to be on the giving end of the all too familiar This Isn't Working Out But We Can Still Be Friends Speech, which in case you didn't already know is complete bullshit 97% of the times it's given. But I'm talking about asking someone out on a date and getting shot down rejection here.

Storytime:
At work today a girl asked me if I wanted to go to a movie with her tonight. The complete and honest answer would have been "No." Simple answers aren't that simple though. I don't have much experience being on this side of rejection, folks. Does anyone know the nicest way to say No? I couldn't think of one. I made a lame excuse, that I had "a lot of stuff to do today." I feel like an ass.

Saying yes was out of the question, sorry. I get the feeling some people, probably including the girl in question, are thinking "Oh, she wasn't pretty enough for you, you shallow pig?" If you mean "not pretty enough to make up for her annoying high-school mentality and the complete incompatibility of our personalities," then Yes, she wasn't pretty enough.
(Note to the Dense: The point of that last sentence is that I'll date somebody who's not attractive if I like their personality, and I'll even date somebody without much personality if I like their looks. Both is best, but having Neither is unnacceptable.)

I do feel bad about it though, because I've been shot down plenty. A sympathy or empathy date, or whatever would be bad though. Not only would I not be enjoying myself, so I'd make lousy company, but it would probably lead her on, too. I know how that only makes the eventual rejection worse.

I may be putting too much thought into this. She only asked me out to the movies, I mean. I doubt she had her heart totally set on me or anything. And I could have done worse than claiming to be busy.
I could have said, and I quote: