I am really enjoying the new Panaracer RiBMo 1.5"s I just put on my new commuter. Goofy name and I was initially a bit surprised about a fairly pronounced V profile to the tread, but in practice, they are working out fine.

I've been on 1.25 Panaracer T-Servs for a while on a different bike and while they were OK -- smooth, easy rolling, light and fast -- they were definitely not up to Marathon par for flat protection. The RiBMos definitely have more meat to them, while being substantially lighter than Marathons. No idea about longevity, so far, but initial impression is all out goodness.

If these don't work out, I'll probably try Marathons next. I've rode them on a few different bikes and know what I'm getting with them, and not that I dislike them at all, but just wanted a lighter tire.