Recommended lens for night photography? (Nikon)?

I've been doing some night photography lately and it's truly amazing. However, since I just started I've been shooting with a kit lens (NIKKOR 18-105mm DX VR Lens) and my D7000. I'm looking to see what type of lens would be of most benefit for my photography.

I'm looking for a lens that'll work on the crowd (portrait, group pics, etc) as well as the DJ.
I was looking into the AF-S NIKKOR 28mm f/1.8G Lens, what do you guys think? -- Feel free to recommend multiple lenses. Any other tips will be appreciated too.

Also, what type of flash would be recommended for this also?

Just keep your 18-105 and get a speedlite.

The 28 is too wide for portraits.

Buy an SB-700 or 910 and a ttl off-camera cord. Your local library will have some photography books related to flashes - read them. Using a flash will be difficult if you don't practice first.

If you want a new lens just for the sake of buying a new lens, get a 35 DX.

The 28 mm lens is far to wide for shooting portraits, but not nearly wide enough to shoot landscapes.

For shooting in low light, the most used lens is the 24-70 mm f/2.8

The Nikon 50mm f/1.2 AI-S. It is manual focus but so fast. I use one on my Canon 5D. It is very nice.

Get the 50mm f1.4 With the D7000 that's a really great portrait and all around lens and it's fast.