I really like most of the Logitech lineup.
For under $40, the K360
looks nice. I have the older model, the K340
which I am using right now as a matter of fact with my laptop, sitting in my recliner.
I'm not sure why the K340 is so much more expensive, but it might have to do with the fact that I don't believe it's a current model. I think I paid around $50 for mine. It's a very solid-feeling keyboard and the keys have nice feedback, although have a little more "spring" to them. I have had it for at least 2 years, and I can't remember the last time I had to change the batteries.
For around $80 you can get backlit with the K800
, which I have on my work rig. It comes with rechargeable batteries and I leave it on 24/7 and have to charge it about every 3 months. The keys have a nice feel and it's easy to type on, but I would recommend a wrist rest.
Both of them use the unifying dongle, which I prefer since I also have several Logitech mice. I have 2 other models of keyboards, but they are larger and don't get as much use.
I do not use them for any games, only work-type stuff.
Just my 2c worth...hope it helps,