Originally Posted by icanhazburger
I tend to photograph anything, but I do mostly wildlife, flora and fauna etc. But I want to do more landscapes aswell, including urban.
If you want serious long telephotos for wildlife, it's hard to dismiss the large selection of lenses Canon and Nikon have. Olympus, Sony and especially Pentax have a lot of catching up to do in that area, though Sigma and Tamron have a number of long lenses priced quite affordably for most/all the mounts.
For macro work, all the mounts have some excellent own-brand and third-party options (notably the Tamron 90mm and the Sigma 70mm), though if you want a ring-flash, Canon and Nikon are better equipped there too.
A special mention should go to the Sony
135mm STF lens - this lens is absolutely unique, designed to provide the best 'bokeh' (rendering of out-of-focus areas) bar none.
This thread at Dyxum provides a selection of samples - you'll notice it looks great when shooting flowers. It's manual-focus only, so it's a bit of a one-trick pony, but it does what it does better than any other lens.
For landscape, in the wide and ultra-wide range, choice is relatively limited and costly on all the mounts, thanks to the difficulties of making a true wide-angle for smaller digital sensors. I've heard the Nikon 14-24mm is amazing (and amazingly expensive). Again, Tamron and Sigma do provide (Sigma have the 10-20mm on all mounts, and Tamron have a forthcoming 10-24mm), but a special note should go to the Tokina 12-24mm, which is closely related to the Pentax 12-24mm (Tokina and Pentax both belong to the Hoya group). Olympus have just announced what should be a
relatively affordable 9-18mm lens.
Note that once you start buying lenses, the cost of the camera represents an increasingly small part of the investment - this is why you pick which system suits your needs.