02Pilot
Malcontent
I've used several. The 28/35 is fantastic, but it took me a long time to find one that didn't cost me a spare organ. A nice, if uncommon, alternative is the Komura piece. Very well made, nice brightlines, and a slight tint to the glass that helps in bright sun (the color of this tint varies - of the two I've had, one was fairly neutral and one greenish). They can be found occasionally on eBay for not too much money.