you and i seem to be on a similar track; i started with dual kit lens and i'm on my way to slowly acquiring primes. i personally like to shoot landscapes and portraits.
i purchased tamron 28-75mm to replace my dual kit. i found myself not using 50-200 that much so i didn't miss the tele side too much. the lens has served me well for about a yr. however, i did find myself missing not having wider angle. also, i realized i didn't like the size and how intimidating large zooms are for portrait subjects. so i'm on my way of trying to build a prime kit; i just purchased FA limited 77mm for portraits and planning to acquire FA 43mm limited, DA 21mm limited and possibly DA 15mm limited when it comes out.
take a look at the pictures you took with your lenses and see which focal length you used the most. based on that information you could try to pick out a lens/lenses that fit your needs. and also ask yourself whether you prefer zoom or primes (benefit vs. cost).
for primes, some choices for indoor photos i can think of are:
FA 35mm f/2 $300 - sharp wide open, smooth buttery bokeh, plastic exterior
DA limited 35mm f/2.8 $350-400 - nice colors, good contrast, macro, metal build, bit slower
FA limited 31mm f/1.8 $800 - ultimate lens, expensive, relatively large for prime
if you feel the need for versatility and don't mind the size and compromises of a zoom then Tamron 17-50mm f/2.8 Di II would be a good choice. it can be had for about $300 from prodigital.
hope this helps!
Last edited by ikim002; 12-08-2008 at 08:46 AM.