Two really...
First one was in 2001, met at Tate Modern late morning, couple of hours spent there, especially the Rothko Room, then lunch in in Bermondsey, drinks in Soho, afternoon tea and cake at Liberty of London, then drinks in Hoxton and finally a club in Dalston. Only thing that was planned was gallery vist, rest just flowed. Relationship was rubbish though!
Second one was a third planned date but not the actual third date. After our second date, the guy told me that as I had mentioned that I enjoyed theatre he hoped I wouldn't mind if he took the liberty of booking tickets for a production a couple of months hence, as it was the first thing on in my home town he thought would be to my taste (i.e. a play not a musical). It was a really lovely way of letting me know he planned to be around for a while, whilst giving me an out if I didn't feel the same way. I found it very reassurring. Our actual third date was great too- art gallery, dinner, comedy club. By the time the theatre came round we were well established, but it was brilliant too. He's DH now. (Our first date was another one of those that went from "let's go for a drink at lunchtime" to cinema, dinner, coffee as well).
So I think often the best first dates are ones that become a spontaneous whole day. But a very planned date a wee bit later is great way of showing you;re serious without having to say it in so many words.