I have been asked quite a bit about my experience with lenses for my digital SLR of late, whilst this topic will bore a few people, to save repeating the story again, here it is.
In chronological order...
Jan 2007, I bought a Nikon D80 and with it the 70-300 f5.6 G lens as well as the 17-55 f3.5 G kit lens.
Feb 2007, I replaced both of the above lenses with a Nikon 18-200VR lens (f3.5-5.6) which is a great, versatile lens. I found the 70-300 G lens slow and pretty useless hand-held. Once I had the 18-200, it seemed crazy to hang on to the 17-55. I lost a bit of money on both the 17-55 & 70-300 but not so much since they're not that expensive. Tip: Do not buy these cheap lenses when you get a camera, or if you do think about buying them, think about buying something else other than a DSLR. I also bought the Nikon 50mm f1.8 prime lens. It's a great lens, especially for under £100 - recommended for portraits - I don't use it as much as I perhaps should but I certainly wouldn't sell it, unless I got tempted into the f1.4 ;-)
Mar 2007, bought a 10.5mm Nikon Fisheye. Wonderfully sharp and creative lens, but I just didn't use it very much. I sold it later in the year, I didn't really want to sell it - but it seemed silly it just sat there. I can imagine I'll get another at some point :) Whilst I was in the states I picked up a Nikon 60mm Macro prime f2.8. A wonderfully sharp lens, fantastic for portraits but pretty difficult to use in any Macro situation on account of needing to get real close. I eventually (somewhat reluctantly) sold the 60mm Nikon late in the year since I simply didn't get any use from it.
April 2007, bought a Tokina 12-24mm f4 wide-zoom. Fell in love with this lens and the sharp, wide images it takes. I used this most of the time, more so than the 18-200vr, which I used mostly for shooting pics of the kids playing football. I've now decided to sell the 12-24, only because I want faster lens' and Tokina have released an 11-16mm f2.8 which is supposed to be excellent and gives me the opportunity to replace the 12-24, which I would really recommend to anyone. Unlike most 3rd party lenses, the Tokina 12-24 (and 11-16) are really well constructed and comparable to Nikon quality; the 11-16 is apparently better than the Nikon glass... I'll have to wait and see to confirm that when mine comes!
May 2007, I fancied a stab at shooting Macro so I picked up a second hand Sigma 150mm macro. I disliked the lens when it arrived because of the construction quality and I could rarely achieve decent results with it in Macro. This was frustrating and I only had the lens a month or so before I sold it on and got my cash back.
June 2007, after using my mate Bob's 24mm AFD prime f2.8, I picked one up on Ebay for £120 or so. This is a great little lens, very fast, great field of view and very sharp. It's also quite small and is perfect when I want a smaller, lighter camera (I take the battery grip off and just have this or the 50mm on). I can't imagine I'll ever get rid of this one and it's highly recommended - and I will use it even more now I've got shot of the 12-24mm for an 11-16mm, since the 24mm angle on digital is practically identical to old 35mm on film.
So, mid-way through the year and at one point I'm sat there with 7 lenses (one more than my nice bag can fit). All a bit silly and by the end of the year, some sense hit home and I'm back at a more rational collection of;
Tokina 12-24mm f4, Nikon 18-200mm f3.5-5.6 VR, Nikon 24mm AFD (mainstay lenses)
Nikon 50mm f1.8 and Nikon SB600 Speedflash unit.
Having had and sold the following;
Nikon 17-55 f3.5-5.6 G, Nikon 70-300mm f5.6 G, Sigma 150mm f2.8 Macro, Nikon 60mm f2.8 Macro, Nikon 10.5mm F4 Fisheye. The only one I kind of regret selling being the 60mm and occasionally when I find myself amongst some nice/interesting architecture or scenery, the Fisheye.
So, into 2008 and first off I get myself a Camera Body upgrade, much to the amusement of Kilburn and to the despair of my wife, who had bought me the D80 as a 40th gift. Sentimentality didn't really come into the D300 decision, it's a terrific camera and no Kilburn, there's no interest in a D3, I just don't use my gear enough (yet!) to warrant anything that silly (i.e. the cost of a small car).
Then I start wavering about buying a faster zoom, with VR of course (i'm not a fan of tripods) and specifically the much vaunted 70-200 f2.8 ED-S VR (££). I'm there in San Francisco, in a camera shop, twitching and I walk about with the 80-400mm VR monster. A terrific lens but really (for me) it spent too much time seeking focus and it was just a bit too big to haul around. A make or break day at the zoo assured me that I would sell it and I did, next few days, losing a little but not a lot. I guess it depends what you want a zoom for, the 80-400 has amazing reach (especially in a high rez camera where you can happily crop) but I think I'd prefer something with a much faster aperture and that's where I'm heading.
Then I see an article about the new Tokina 11-16mm, super-sharp and lo and behold it would be great to have that, utilise my 24mm AFD more and sell on the 12-24mm (which I still like, but there would be no point keeping).
As I type, I'm tracking various f2.8 70/80-200mm's... we shall see.
They're right when they say you can't go back when you've used f2.8 stuff though - or semi-pro/pro lens'. There's just something about the construction of the gear and the clarity of the optics.
I'm also a new man because of the camera kit insurance... I feel relaxed and inclined to take it places, which is all well and good. Some poor bugger at work dropped his D3 and new 14-24mm Nikon FX lens (supposed to be the dogs!) on the floor and snapped the lens... uninsured, ouch.