DA21 Ltd - great for street photos, AF is very reliable and the unusual lens hood helps you to remain unnoticed. Just a touch too wide at times when you can't get close.
DA35 Macro Ltd - AF can miss and it is a long (and noisy) spin to the near end stop. 35mm is a bit short for macros - you have to get really close. Nice lens otherwise.
DA40 Ltd - also reliable and fast AF but somehow I'd never liked the focal length for street photos.
DA70 Ltd - great for short tele people shots when you want to blur the background.
Basically, you can't go wrong with any of these, but I'd recommend the DA21 to start with