In the modern era we've been noticably deficient in great OT's. Gee, that's news isn't it, LOL. Since I have no awareness of the OT's of earlier eras and my grandpa has passed on and can't coach me I guess I'll confine my comments to more recent players.
I don't think we ever had an OT to equal Jimbo Covert and the pairing of him and Van Horne are the best twosome in modern times. Individually both Dennis Lick and Andy Heck were very good LT's but we got Heck later in his career and back problems ended Licks career early. Let's hope we have better luck with our more recent Badger OT.
Aside from Keith Van Horne the "Big Cat" would have to be all time favorite at RT. I see a lot of him in J'Marcus Webb too. I like Tait and either LT or RT but like Lick his injuries kept him from giving more than a few good years. One guy I didn't see on here is Lionel Antoine. Another first round pick with an injury foreshortened career.
All time worst OT: is there any doubt? Stan 'the woman" Thomas otherwise known as the matador, ole'.
LOL i'd say "q' mitchell and to a lesser extend troy auzenne not very good, but stan was awful- remember ditka railing against what a bust he was in camp his rookie year( didn't take long did it?).. and #1 pick george rice in 1966 a complete bust( guess after butkus and sayers in 1995, 1996 was going to be bad luck..lol)..
Also blake brockenmayer, while got him later in career and only started for 2 years, pretty good on the left side