Hopefully you know what I mean. You pick up a comic featuring a character called "Something man" (anything other than Superman), but after 10 minutes reading you're pretty sure you are reading the writer's take on how he or she would write Superman...if DC gave them the go-ahead to write the great man exactly as they wanted to.
Some of this type of material can be very good, after all if writer is good quality, and can do own thing result is always likely to be better than "average" mainstream Superman...in last 20 years DC editorial control of Superman hasn't been totally wonderful.
Anyway here are my two recs:-
1/ Alan Moore run on Supreme. This really does read like Alan Moore had a ton of material that he would have liked to use to write Silver Age Superman stories, DC gave "gig" to John Bryne, so Alan M used them here instead. His "Superman" is a fun relaxed character, and series has a ton of "kryptonite" weirdness (think of the days when Red Kryptonite could do just about anything), a novel take on the Legion. and a starring role for "Krypto". I'd say it's good rather than great (certainly by the writer's own standards)...but still much better than a lot of the official DC Superman material.
2/ Mark Millar on Huck. Not a high powered version of Superman (Huck is strong and fairly fast, with one additional power...really you'd expect Spider-man to beat him in a straight up fight). But in Huck's own world he's the strongest guy around...this felt to me like a take on the golden age Superman (but would value other opinions on that, read almost no golden age material). But the fantastic thing about Huck is his character...his absolute faith in people and his desire to help. I think this is an exceptional read, streets away from the rather amoral violent slapstick Mark M often turns out.
Anyway those are my two picks for non-Superman Superman material. Very interested to see other suggestions.