For world champions who had to wait whilst being number 1 , liston comes to mind. Lewis had to wait quite a while to get his shot at holyfield although technically you could say holyfield had to wait a while for his shot at lewis. Arguello at sfw never got to the lineal champ. It really depends on what the ts counts as a champion. Like bodhi says, hopkins was number 1 for about 6 years before unifying and claiming other titles.
He became the #1 contender according to Ring in 1960 and kept that position in 1961. Got his shot in 1962. Hardly comparable to how long some other fighters were ducked. The myth of Liston having to wait decades before receiving his shot has been inflated for years but isn't based on facts.
possibly someone during WW2 and a large part of the answer depends upon whose ratings we go on. sorting out champions can be messy at times but number one contenders is more subjective still Ring magazine produced the accepted ratings for many years, but there was a time before The Ring and also a time after Ring ratings have been accepted. and there were always alternative ratings by the NBA and NY even in Ring's heyday prior to the 1920s i'm not sure about - did the Police Gazette publish ratings or just list the champions ?
Hagler was on the shelf for a while definitely. Not many fighters plead with orgs to move them down in their rankings. ----------------- I think you've got to split it into the single title era, then the ''alphabets when they meant something'' era and the ''2000's onwards''. Some fighters don't want to face the ''real'' champ and are content to hide behind a strap for as long as possible.
Maybe im mistaken and my memmory is playing tricks, but i seem to remember J M Marquez Waiting on Naseem Hamed for an overlong period, with Hamed finding other dance partners, Ken Buchanan had to tred contender water after the contravercial Loss to Duran, until past his best and getting a "Guts" Check - Dejuses upsetting Duran first time round did not help his cause for a prompt return.
Champions & Fighters ENHANCED their reputation... this is a topic I was going to do a thread on, may aswell get it started. the "accepted" Champion(s), were the King(s) of the Hill, and Boxing Managers would push their lad after they beat excepted and noted fighters from other areas (Contenders), this could go on for a great many fights before they got too the Champ. and just like now, for some with fewer fights, for others never! Ratings for many years after their established existance, were always disputed and strongly & rightly disagreed with... there is a Boxing News peice from 1939, stating that they (the Ring Ratings) were entertaining at best and at worst "laughable"... this is infact TRUE, as nothing can be precisely accurate, especially when dealing with hundreds of TOP Fighters from Boxings Best Nations. Ratings became the main stay however and are definately a good guide and measure IF they are "untainted" & Honest... BUT I agree they are NEVER perfect or all inclusive. Top Fighters can still Enhance their Reputations, as long as they can get near the right fighters!
Not sure about number 1 stoof but Jose Napoles sure hovered around Carlos Ortiz for a long, long, long, long time.