I have to say I prefer situational openers. Of course, there is less freedom for your choice of girl because the situation has to be right, but the strike rate is definitely much better. Plus, the more you use situational openers, the more accessible they are in your head and you can use them more often.
The most recent one I used was when I saw a girl fixing her hair in the reflection of a window..I came up and I asked "hey, who's your friend, she's kind of cute..can you introduce me" while motioning to her reflection. From there the Number Close was easy since she was laughing, and I think felt a bit insecure that i'd spotted her checking herself out. hah.