Anything in 35mm is going to look good compared to 110!
Originally Posted by Truzi
Seriously though, "new" Portra 400 (i.e. the stuff that came after 400NC/400VC) was a big step up in resolution and colour fidelity and that happened maybe 5 years ago. I strongly recommend you give it a go, and some Portra 160 too if you want the same excellent colour accuracy with even more resolution. Ektar is even finer again (finest colour film there has ever been - it can be hard to print manually because it's difficult to see the grains under a magnifier!) but has very high saturation. It's good for landscapes but bad (IMHO) for portraits unless postprocessed digitally.
Fuji also makes some colour neg but you should really try some Velvia while you can. Can't make prints from it except digitally, but you can look at the chromes directly and/or project them. They're like little colourful jewels of perfection all in a line.
I'll assume you don't do your own processing/printing at this point and therefore ignore B&W options. But it's easy and worth considering if only because it costs about $1/roll for processing - see the FAQ in my signature.