First post here, but I thought I'd chime in as I've tried quite a few.
1) Vivitar Series 1 135mm f/2.8 "close focus" Komine lens. - Not technically a "macro", but it goes 1:2 without an adapter. Beautiful bokeh.
2) Kiron 105mm f/2.8 (also sold as Vivitar 100mm f/2.3 and "Lester A Dine" 105mm dental lens) - 1:1 without an adapter, SUPER sharp wide-open, nice (neutral) bokeh. Excellent color rendition.
3) Minolta 50mm f/3.5 Rokkor - A much more "manageable" focal length for non-tripod use. Very sharp wide-open, lovely Minolta bokeh and color rendition.
Check out Contax Zeiss. They are amazing lenses, even better than CZ Jena. I have a 50mm / 1,7, still amazed at the lovely bokeh and colour resolution after all these yrs
Oh yeah the Flektogon 35mm is a splendid lens. Min focusing distance of only 0.7, it is very sharp and yields saturated colours. Took me a while to collect the entire collection: 20mm, 35mm, 135mm
Old Tamron 90mm f/2.5 1:2 SP macro (Yashica Contax mount), awesome, combine that with tubes.. epic. Otherwise reverse mounting 50mm, 28mm etc is amazing too. But big light loss, not a prob if you want to make your own macro LED light ring with some nice bright 1W LEDs.
Got my Tamron for < $10. A long with a bunch of Yashica Contaxt mint condition primes for < $10 each. So lovely.
I'll be shooting macro videos when I got something to shoot/idea. I want to make something long, not shorts for Vimeo etc.
I just got a 35mm Flektogon.. superb lens. An extender would be necessary to really push the macro function though. I'm guessing it would be possible to get a really unique look with a wide angle converter..
The 100mm Macro Rokkor by Minolta is great and another one I like a lot is the manual Tamron 90mm 2.5 SP, which is tack sharp, has beautiful bokeh and looks good even at normal distances.
I have the Vivitars mentioned above, the 55mm and the 90mm and the 55mm is the one I use the most because it is light weight (the 90mm is a brick) and has a sort of lens hood by virtue of the recessed lens They are both excellent. I don't see a difference in sharpness. The 55 was recently retested online and it tested pretty high. I paid $13 for my 55mm and $175 for the 90 (with the 1:1 adapter) so no question which is the better deal. I prefer the color of the 55mm to the 90mm. You can also just buy a lens spacer on eBay for ~$10 that turns your old lenses or even m43 lenses into macro lenses. They work pretty well.
I have Leitz Summicron f2,0/50, Leitz Summaron f2,8/35, Leitz Elmarit f2,8/90. I have had them sinse the 1960th together with my Leica M2. They now have with GH2 come to live again with the M-adepter. They work perfect with my GH2 and I specially love the 50 mm Summicron.