I can whole-heartedly recommend Chancellors' Courts. RN's alright, but the decor and fixtures are over 10 years old now, and starting to show it. Chancellors' is still in great condition, the rooms are only slightly smaller than the Connaught Old Quad ones, and I cannot over-emphasise the benefits of having a double bed. But either way there's the (very excellent) Glen JCR.
But if you've selected Small Halls as your first choice you're very likely to get it, seeing how few apply for it as their first. The majority who don't get their first choice are those who select en-suite at Glen or Monte and end up at Orion's Point. Trust me. I've seen the stats.