Hi, at the mo I have and use on my A7 via Novoflex adapters...
Minolta Rokkor - 24 and 28mm f2.8, 35mm f1.8 (I had the f2.8 and liked it so much I swapped it for the f1.8,) 50mm f1.4 and f1.2, 85mm f2 and 135mm f2.8 and f3.5. I also have a Sigma 50mm f2.8 macro in the same fit.
Olympus Zuiko 24 and 28mm f2.8, 50mm f1.8 and f1.4, 85mm f2 and 135mm f3.5.
Canon FD 28mm f2.8, 50mm f1.4 and 85mm f1.8.
The only FE lenses I have are the 28-70mm kit lens and the 55mm f1.8.
I think that all of the old lenses are perfectly useable and they look good to me even at the very edges when stopped down a bit. Of course wide open they're not going to compete with good modern lenses especially towards the edges but at their best they are good and the quality they're capable of giving continues to please me.
I've done quite a few comparative tests and to me there's nothing really between the 24 and 28mm lenses but if I had to choose one it'd be the Minolta 24mm.
The Minolta 35mm f1.8 is very good and I can only really fault it at its very widest aperture which I'd reserve for emergency and artistic use as the bokeh isn't the best, but I wouldn't expect great things from a 35mm.
I think that the Minolta 50mm f1.4 is the best 50mm followed by the FD or possibly the Zuiko f1.8 and then the Zuiko f1.4 but the differences really are just sharpness and fringing at the widest apertures and once stopped down I'd say that they're all good. I do like the Minolta 50mm f1.2 but I like it for its character rather than it's optical quality
To put these lenses into perspective I'd say that none can live with the Sony 55mm f1.8 but for me that's not the point of them. The Sigma macro was a bargain and I'd say that it's very good.
For me the 85mm's are similar to the 50's in that the Minolta is the best followed by the FD and then the Zuiko and again the difference is sharpness and especially fringing at the widest apertures, stop them down and they'll all ok.
The best of the 135mm's is the Minolta f2.8 and I'd say that there's noting between the Minolta and Zuiko f3.5.
I've also used the Minolta and Olympus lenses on my MFT cameras via cheap adapters and they work well. I'd describe my photography as casual but deliberate and old manual lenses are mostly ok for me. I use the FE 55mm when I need to be a bit quicker.
Sorry for the long reply, but just one more shot... I took this with my Panasonic G1 and one of the 50mm lenses. It's via Photobucket which seems to mangle my shots a bit but on my screen this is lovely and sharp. I really couldn't ask for more from such a cheap set up