ANY prime f/2 or faster with IS. & at this point it's been so long that I mean any, from 14mm to 135mm, would make me happy. These new f/2.8 wides are a step in the right direction & certainly the first non-macro non-L primes we've seen from Canon since 1995, but even Canon acknowledged that their primary purpose was as compact video lenses. I've already got a 24-105 f/4L IS, why would I drop 90% of what I paid for it on a prime in the same focal length that's only one stop faster?