I can highly reccomend the Nikkor 28/2 AIS - lovely old school glass.

i have just bought a Samyang mc automatic 1:2.8 f=28mm (canon FD mount) and is sharper than the (probably bad copy) Canon 28mm 2.8 (canon FD mount) i used to have (that one cost me U$60)
, the funny thing is that i manage to get an unopened box, so my samyang is brand new :)
it cost me arround U$60

also, i now have a Canon 20mm f2.8 (canon FD mount), (that i get on a trade, i exchange a 80-200 f4 canon fd + the canon fd 28mm 2.8 + U$40) and i must say that i absolutely love it, specially because i can place a wide adapter in front, of course loosing some sharpness in the corner but not on the center, but, i still can use it wide open with the adapter, and i actually use a 58mm wide adapter with step down rings ( being the canon fd 20mm, 72mm in the front) without any vignetting, so i can have something like a 15mm at 2.8; the wide adapter is a Vivitar series1 0.43x threaded in the back at 58mm, and that cost me U$15 on B&H a few months ago

>Anything against Panasonic 25mm F1.4 ?
Apart from the focus-by-wire, not really, but it's not for me, and I'm just looking at possible alternatives.
The reason I looked at Leica lenses was because I may buy an M6 sometime in the future, and because I have a friend who already have one and a GF1, it could have been a nice photo/video combo.
I may start buying a good canon FD body (ie F1), to use the FD lenses I bought lately. I will look at M6 if I'm enjoying 35mm film photography