Which nikon telezoom should I investigate?

Please name the best Nikon Telezoom, not too expensive. I use a Nikon D40.So preferably something suitable for this version, thanks. Also, it should be able to handle dark conditions rather well. Now, what type of inexpensive yet good telezooms are there!

The least expensive telephoto zoom would be the 55-200 mm @ $250, next the 55-300 mm @ $400.

When you add that you want to shoot under "dark conditions", inexpensive flees the room.

The best telephoto zooms for use in low light are the 70-200 mm f/2.8 @ $2, 400 or 200-400 mm f/4 @ $7, 000.

As you can see, lenses used for shooting in low light are NOT inexpensive

It's really obvious you know nothing about low light shooting because you've done no research at all.
low light is always tricky and unless you know exactly what you're doing you'll fail every time.

I'd suggest some serious reading and research into low light photography. Then you'll have a better idea what your actually asking for.

Here's an article to start with.
http://en.wikipedia.org/...hotography

Nikon 55-200mm, 55-300mm, 70-300mm are the only ones below $550.

For low light, you're gonna have to buy a more expensive 70-200mm, which is 4x more than the price of lenses above.

Here's a Lens Buying Guide - http://www.the-dslr-photographer.com/2009/11/buying-a-lens/