Nikon kit or body only?

I'm thinking of getting the D3100 as my first DSLR and I was wondering if I should just get the body and focus on a good lens? Or just get the kit and the 18-55mm lens should be enough? I'd be shooting landscapes/portraits. Nothing extreme

It looks you are starting with photography. Get the kit and buy a new lens later when you feel you need it.

The kit lens does a reasonable job for both landscape shots and portraits. Unless you specifically want to go for a more expensive standard zoom such as the Tamron 17-50/2.8, there's nothing wrong with it.

I'd get the kit lens as a versatile default lens, and then buy additional more specialized lenses.
For landscape, that'd be a ultra wide angle lens such as the Sigma 10-20 f/4-5.6 (better than the more expensive f/3.5 version!), Tokina 11-16/2.8 or Nikon 10-24mm.
For portraits, i'd get a 50mm/1.8G AF-S or 1.4G AF-S. The "AF" versions won't autofocus on a D3100, so getting the AF-S versions is definitely recommended.

Edit:
Ah yes, i should have mentioned that bit explicitly: Don't get a second lens right from the start, but use the kit lens. Once you're feeling limited by the kit lens and you can specifically name the reason why you feel limited by it, buy a second lens to fix that problem. That shouldn't be earlier than after having used the kit lens for at least half a year or so. Don't spend $500 now on a lens that might not be what you really need, gather some experience with the kit lens first.