At the risk of upsetting just about everyone I think the most significant aircraft the RAF has ever operated is the Tornado in all it's guises.
I genuinely think it was a big and significant mistake.
F-4 and Buccaneer replaced by F-15A and E - we'd have been the canine's proverbials.
Not sure what was the "big and significant" mistake you refer to in this post. The Tornado? The replacement quoted?