Williams, who scored twice during the third-Test win over the Springboks in Johannesburg, feels that the quality of rugby produced by the tourists, together with the family atmosphere created in camp, provided the perfect repost to those who claim the Lions have no part in the modern game.
"We proved the Lions have a massive future," said Williams, who was a previous Lions tourist in 2005.
"I've never been on such a good tour and it's the toughest rugby you're ever going to play. Playing for the Lions is the pinnacle of my career and it is something that should continue for ever."
Williams and his colleagues played their part in a truly stunning three-match series against the world champions; one that had supporters on the edge of their seats throughout and could easily have gone the Lions' way.
Very few Test fixtures can match the drama and intensity of the three encounters in Durban, Pretoria and Jo'burg, and Williams has no doubt that such special occasions illustrate exactly why the concept of the Lions should be held sacred despite the demands of the professional game.
The 32-year-old Welsh winger epitomized the spirit of the Lions as he battled back from the disappointment of non-selection earlier in the series to play a starring role in the final-Test win.
Williams was a constant threat to the Boks in that match, continually looking to get his hands on the ball rather than waiting for glory out on his wing.
For the Ospreys star his tries were a bonus, but the real pleasure came from the performance of the team as a whole and, of course, from the win.
"It was a massive game for me. I know eyes were on me because there were a lot of doubters out there and I knew it was my last Lions game so I would have to perform.
"I wasn't going out there to dazzle but to work in players outside me. I got involved as much as I could, played first receiver, second receiver and nine when I had to.
"I could see when I got my hands on the ball that the Springboks were looking for me to do something and when I was offloading to other players, that gave me as much satisfaction.
"We were a tight-knit family on and off the field from the start. We worked hard from day one and we felt we deserved something out of the tour."