Portrait lenses for Nikon D40

I currently use the Nikon D40 kit lens - 18-55mm f/3.5-5.6 with my camera. It's a good, versatile lens that takes decent photos at different ranges, but I yearn for a lens that gives me better depth. On my quest to research which lens to get, I couldn't find a place that gives concise information with an at-a-glance comparison grid so here's one I created based on research on various forums, including reviews from Amazon and B&H.

Here are my requirements, which helped narrow the long list from Nikon down to the final four.

• Auto-focus has to be functional on the D40 camera body
• Costs < $800
• Good for portraiture, provides more dramatic depth in portraits (technically less depth of field, which makes the subject "pop" in the frame)
• Easy to change
• Really good to have: faster speed, allowing for better photos under low lights. This means a bigger max. aperture (small f-stop number)

Category/ Lens	Nikon AF-S Micro-Nikkor 60mm f/2.8G ED Macro Autofocus Lens	Nikon AF-S Nikkor 50mm f/1.4G Autofocus Lens	Nikon 16-85mm f/3.5-5.6G ED VR AF-S DX Nikkor Lens	Nikon 18-105mm f/3.5-5.6 AF-S DX VR ED Nikkor Lens
w/1.5 crop factor applied	90mm	75mm	24 - 128mm	27 - 153mm
Price	$520 + shipping	$470 + shipping	$600 + shipping	$300 + shipping
Weight	15 oz.	9.9 oz.	17 oz.	14.8 oz.
Pros	Sharp focus, Durable, Strong construction, Consistent output, Easily inter-changeable	Sharp focus, Fast focus, Consistent output, Lightweight, Strong construction, Biggest max. aperture	Sharp focus, Consistent output, Strong construction, Easily inter-changeable, Durable	Sharp focus, Durable, Fast focus, Good range
Cons	Pricey, no VR	Slightly short on the portraiture range, not best bokeh esp. with small lights (e.g. xmas lights), not sure if it's going to look significantly different from 18-55mm, no VR	Heavy, slow focus
Good for (on B&H)	General purpose, Portraits, Special effects, Macro	General purpose, Night photography, Special effects, Sports/action, Landscape photography	General purpose, Portraits, Landscape photography, Upgrade, Wildlife	General purpose, Landscape photography
Notes			Used by pros and semi-pros

A quick legend on the different abbreviations on lenses (aside from the max. aperture, and focual length in mm):

• AF-S: Type of lens that has an internal auto-focus motor built into the lens. D40 can only use AF-S, AF-Im and AF lenses but auto-focus is only available in AF-S lenses. IX lenses for full-frame cameras cannot be used.
• VR: Vibration reduction means less blurry photos
• ED: Stands for extra low dispersion, has to do with the type of glass used in the lens, which lessens color "fringing" on photos
• IF: Internal focus with no change in the lens length. This means a lighter weight and more compact lens.
• DX: Lenses for smaller-frame (i.e. non full-frame) cameras such as the D40
• G: No aperture ring built into lens, OK for D40 or other DSLRs where the camera is able to set the aperture

I also enjoyed the following articles from the Digital Photography School regarding lenses:

• Good basic explanation on different types of lenses
• Digital Photography School's readers favorite lenses, conducted in late 2008. Note that auto focus for the Nikon 50mm f/1.8 lens on this list is not supported on the Nikon D40 body.
• Most bought cameras/gear on Amazon in Q1 2009. Just something fun to read to see what people are buying. Not necessarily applicable to your needs.
• Best lenses for wedding photography

To save a few bucks, try these sites for used gear. I haven't bought from them personally, but a couple good friends have and recommended them as trusted sites.

• www.fredmiranda.com
• www.keh.com

UPDATE:

• Technically, focal lengths of 85-100mm is best for portraits. For the D40, that translates to approximately 57-67mm focal length for lenses. So if you want to go by the books, get a lens that covers the range of 57-67mm. Note, however, that is talking about portraits taken at 8-10' from the subject.
  
• If you're leaning towards getting a faster lens, another thing to consider in regards to focal length is whether you want a lens that you will use a lot, whether this is one of the few lenses that you will own (as is the case for me). If so, it may be good to take a quick poll of focal lengths on photos you take to see if you find any patterns. For example, if you take most of your photos in the 20-35mm range, then you may want to get a lens that covers the range. I currently have my eyes on the new AF-S DX Nikkor 35mm f/1.8 lens that retails for ~$200!