I have mostly Minolta lenses. Of them, I really like the 20/2.8, 28/2, 85/1.4. I also find the Konica Minolta 28-75/2.8 a really nice lens. Mine is a little sharper at the long end than the wide end, but usably sharp even wide open. The Sony 70-300 G is also very sharp and fast focusing. I only got it a few months ago and wish I had gotten it sooner. It's usable even wide open and the best zoom lens I've ever used.
The Sigma 70/2.8 Macro is a very sharp lens. I use it quite often, but it does have some focusing issues. Unlike the Minolta or Sony lenses I've used, it auto-focuses at a different position if the lens is focused from infinity or from the close focus direction. It's not a big deal at longer distances or smaller stops, but at close distances I've had some focusing problems.
The 35/1.4 is good stopped down and reasonably sharp in the center wide open (sharper than the 50/1.4 wide open but not as sharp as the 85/1.4 wide open), but it's rather big and heavy for what I consider a f/5.6 lens. I don't think it is ever as sharp as the 28/2, but the 35mm does have better bokeh. I have also had some focusing issues with it that I'm trying to work out with AF adjustment settings, but I don't really have a handle on it yet (maybe it needs different settings for different focus distances). I did find that I couldn't use the same setting for f/1.4 and f/2, the focus shift between these 2 stops was enough that when the f/1.4 shot is sharp, the f/2. shot is out of focus. I've sometimes had great results from this lens, but often feel that the results are not what they should be. I've read that there are some tweeks to the design for the Sony version and it may well be a much better performer.
I'm not completely happy with the 50/1.4 I have (old version with 49mm filter ring). It is not bad at f/2.8, but I find it unusable at wider settings. Like the 35mm, I also have had focusing issues with mine and I don't know if the AF adjustments are constant with focus distance. I've had some out of focus shots with this lens that should have been simple and worked find with other lenses. I really hope that Sony comes out with a Zeiss replacement for this lens. I like using 50mm a lot, but I'm not really happy with this one. I do sometimes wonder how it compares with the current Sony lens. I also wonder about the Sigma 50/1.4, but I've read that it has focus issues and based on my Sigma 70mm experience, I believe it.
The Minolta 135/2.8 is a decent lens and a nice small longer lens to stick in the bag. It focuses quickly and accurately. It is sharp, but has rather low contrast. I don't use 135mm all that much and don't want to spend the money or carry the weight of the Zeiss 135 although I'm sure it would be a much better lens.
Unlike other reports I've read, I've never been very happy with my 24-105. It is a little sharper at the wide end than the 28-75, but I find it rather soft at the long end. Maybe part of my problem is that I like working hand held in low light where I'm not using it at f/11 where it seems to work best. I would like Sony to make a G version of this lens that works as well as the 70-300.