I always thought the seatstay/lug/clamp on my 88 mondonico was very clean, simple and elegently done (photo on link below). Not sure exactly what style or who makes the lugs, any info would be appreciated. I believe this frame was one of the first batch after Mondonico left Guerciotti in 1988 but bike history always seems a little hazy so who knows for sure.
http://imagedeposit.com/