I've been very happy with the lens kit I've built over the months/years. I've found what I liked, didn't like... been able to get something that I'm really happy with (but is still far away from perfection).
I started out with a Nikon 18-105mm when I bought my used D200. I wanted a lens that had a good zoom range, had alright IQ, and was cheap. Because, with that camera and that lens... I was already $1000+ in a hole that I had no idea if I'd truly like. Now that I think about it, I have never had much experience taking pictures... but my eye for pictures has gotten so much better over the years because of all the experience.
This lens taught me some very important things. Primarily... it being a super slow lens. f/3.5-5.6 is dreadful looking back. And... to fix this... there are 3 things you can do. 1) Get a faster lens, 2) Get a flash, 3) Get a camera that has usable high-iso.
Getting a fast lens also means thin depth of field.... which is something I've found to love and want in my photographs. Flash is something I've contemplated and contemplated again... but I can never get around the feeling of "being the paparazzi" with having one of those blare their ugly non-natural light all over the place... and looking like someone who wants to shoot people down with their camera. And the high-iso camera was out of the question because, FX is expensive, and I just bought a D200.
Other faults I had with this cheap zoom was its distortion. It wasn't a problem with things like people or furries, but if it was a building or a sign or something with straight-lines... very potent barrel distortion on the wide end and pincusion in the rest of the range... it was quite obnoxious.
I also felt that 18mm was "an acceptable amount of wideness" and 105 being "probably as much as I'd ever care to zoom in". The difference between focal lengths also is quite huge. 11mm vs 18mm is HUGE compared to 85mm and 105mm... nearly no difference.
So the 2nd lens I buy a long while later is a Samyang 85/1.4 manual focus lens. It was fairly cheap, it was built well, has an aperture ring which is neat, performs well optically, and has the smoothest and blurriest bokeh ever. Getting used to the manual focus with DoF so thin was quite hard, but once you got the hang of it... the stuff I got out of this lens felt amazing. But 85mm is quite tight. 3ft min focusing distance was just about too long for most of what I want to do, and when I was at that MFD, people's faces nearly filled the camera frame. If and when I do get an auto-focus 85mm, I'd use it purely for the great bokeh you can typically get from this FL or when I want to keep my distance from people.
After this I was able to get a hold of a Nikon 50/1.8 series E lens. This lens is also manual, but super cheap, very fast and easy to manually focus, acceptable bokeh in most scenarios, comfortable focal length... and SUPER TINY! It's Nikon's.... 2nd smallest lens I think? Right behind the 45/2.8 AI-P? Anyways, this is probably my most used lens today. It makes my kit nice and small and easy to handle... I don't threaten people as much as I would with a bigger setup, and I love the pictures.
But then I decided I should get something even more "wide".
So I started looking at 35mm's. There isn't much of a choice really in nikonland. At the time I had the choice of a 35/1.4 AI-S, 35/1.8G DX, 35/2D, Sigma 30/1.4, and a super expensive Zeiss lens. The first lens there is supposed to be $1000 new... but I bought this puppy for $450 on ebay in NIB condition. And man... this is also a favorite lens of mine. My most favorite mechanical lens, fave MF ring, aperture ring clicks are very nice, focuses SUPER CLOSE, has great bokeh almost all of the time, and is in a handy 35mm FL. I must regress, this lens feels less "normal" to me than the 50 does. If I need to be closer to people or I want a wider (but still thin DOF) shot, I'll use this. It's still a fave but not used as much as I should use it.
And now... I wanna go even wider. I look at lots of UWA zooms, and basically settle on the Tokina 11-16/2.8. Everyone loves the build, it's sharp, it's fast, it's wide and has almost no distortion, it's a good price. I buy it. The Sigma 8-16 (which came out later) would be the only lens I contemplate today... but it is MUCH slower vs the Tokina's constant f/2.8. And god... I am amazed again. Everything I hear about it is true. It's simply stunning how wide this lens is. The world feels different when you use it... no longer are you capturing a single person... I can capture everything in a single shot... and so much more than I can care to see with my regular eye. It's a breathtaking piece of glass and makes everything feel so much more open and vast.
And with this great little kit of lenses... I sell my 18-105. I've got my UWA, and 3 fast and comfortable portrait/candid lenses. Just about anything I care to shoot... I can now.
But... There are still things I care to improve.
I keep telling myself I should get a flash... but I don't think I ever will. I love natural available and ambient light... never do I feel like I have the right to just "add some" to make me get a proper picture. If my ISO is jacked high, lens is wide open, and my shutter speed is as slow as I care for it to be... and I can't get proper exposure w/o a flash... I probably shouldn't be getting this picture... and that's exactly what I do. Too bad, so sad. Move on and find something I can shoot.
Manual focus is fun and easy, but there are times where I wish I didn't need to do it. I will probably replace my current lenses with AF versions in the future... but that will happen as soon as I have money to spend (which won't be for awhile). Newer lenses could also lead to possibly bigger apertures too, but $2000 is entirely too much to ever spend on a single lens IMO. Right now at least, anyways.
I do plan on upgrading my body some day too. I love how the D200 handles and I could never go down to a smaller body IMO. I've tried a D7000 in a store once and... my thumb had simply no-where to go on the back. The D400 I hope has a D7000 or better sensor in it. That, or I could finally jump on the FX bandwagon with a D700... or a D800 if Nikon ever releases it. But... yeah... that's way far off and will cost big $$.
Lens wise... I really don't know. Long lenses like 100mm+ just don't sound like they'd impress me. Even a 300mm with some TC's... that's just not my kind of shooting. A macro lens I'd like to give a shot but again... I don't think I'd do much w/ it besides fuck around. A 8 or 10mm fisheye might be fun to mess around with, but the fisheye effect gets old fast, and I already love my rectilinear 11mm with the Tokina.
Anyways... I felt like I just wanted to say that. That's how I've developed and I can't wait to prune and perfect my current kit.
EDIT: latest pictureshttp://www.dropbox.com/gallery/8606967/1/firsthomedrinking?h=0c8025http://www.dropbox.com/gallery/8606967/1/aftermillerstuff?h=c39c64
I know these pictures are far from perfect, but they all come naturally while I take them.