Some Logitech hardware that I have known and loved:

Logitech Mouseman Cordless
This one was weird back in the day. It's a radio mouse (one of the first of them, I think), and it was shaped like a hand. The only really bad side was that it used a 3-volt battery that was rather hard to find (found only from the local photoshop, and it was costly there).
Logitech Scanman/32
(I'm not sure of the model number... must check.) This was a 32-grayshade hand scanner that I have used much more than flatbed scanners. Put simply: It just rocks. The only thing I didn't like about it was that it interfaced with the computer using a proprietary ISA-card-based interface. (Back then, the degree of standardization was what it was...) For a long period of time, I was unable to use the scanner because I didn't have a driver... then I finally found the patch from Logitech's web site when the Internet came about.
Logitech PilotMouse+
This mouse rocked, probably the best non-optical mouse I've used. Light wheel, accurate, relatively easy to clean... much better than "regular" Microsoft wheelmice. I finally needed to replace this when I got fed up with PS/2 connection and the fact that optical mice didn't get clean. Plus, my Intellimouse looks zillion times cooler. (Microsoft, as usual, competes using eye candy factor. However, Intellimouse Optical is a nice mouse, but I digress.)
Logitech QuickCam Express
Ah, the Quickcams. Folks love Quickcams. I like mine, even when the picture is smallish (well, what can you expect from this price class?) The only problem was finding the Linux driver - only the parallel port Quickcams were supported in Linux, and the USB Quickcam driver had to be hunted separately (it works fine, even when it's alpha).
Logitech Wingman Extreme Digital 3D and Logitech Gamepad
I previously had Microsoft Sidewinder 3D Pro, and it worked fine until I got this new machine - apparently new machines have really crappy PC joystick interfaces on board. So, logically, I got an USB stick. While this stick has one button less than MSSW3DP, it IMHO has better button placement. I shall control my 'mechs with this nice joystick.

The Pad, then, was a cheap replacement for my Microsoft Sidewinder Plug & Play gamepad, which was nice but made for smaller hands (sometimes it hurted) and had ridiculously low amount of buttons. This new pad is bigger, and it has 11 buttons (incl. "Start" and "Select" and L/R trigger buttons - though Linux jstest program, for some reason, says it has 15 buttons!

Logitech Soundman SR-30
Okay, any set of speakers is probably better than my old speaker set, and as a "weekend hifist" I can only say that this thing sounds divine even on two channels... Seemed that the headphone jack on the thing only outputted some weak signal and couldn't be amplified without quality loss, but I just screwed up some controls. Blame me. I guess the headphones I use with my computer are useless with these ones (background hiss gets through), I need to use my CD player headphones instead... Well, at least Microsoft can't come up with set of speakers that looks cooler, because I like the design (dark blue/black plastic and gray metal) and the subwoofer part looks rather nice.

Summarization (preceded by gradual realization and cold sweat):

Great hardware.
Sometimes somewhat challenging interfacing with other parts of hardware.