I don't use it anymore because it's simply impractical for work (work demands a minimum of 20mp files), but the 1Dsmk2 is my favourite 35mm format camera in terms of the feel in the hand, the feel of the shutter button, and the sound of the shutter, and I sorely wish I could get that same 'shell' with a newer sensor & processor. (Er, and a newer screen, too.) It may be collecting dust due to not meeting modern requirements, but if Canon released all of their cameras in a limited edition which simply had the 1Ds2's outer case and shutter, I would gladly pay double for them. Love that thing.
The other Canon I'd give a nod to is the 5D2. It was the standard workhorse for years and other things being better now doesn't stop it from still being a really solid, workhorse camera today. It's not my main camera, but it's still my #3 backup body, and with current prices around the £550-600 mark—the same as a new SL2—I've started pushing new photographers toward buying a used 5D2 over any APS-C body, at least for stills.
Other than that, I still get a lot of enjoyment out of Canon FD gear, some of the early 90s EF lenses are still fantastic (the 100mm is the most underrated Canon lens), and my 'old' Mamiya RZ67 Pro II is still my main backup camera. (Adapted to a digital back, it takes the #2 spot behind the Phase.)