There seems to be a rule that all Prisoner Web sites must be as cluttered as possible but I forgive Unmutual everything for this wonderful compendium of bloopers in each episode. Sometimes I just want to revisit the show without doing any heavy mental lifting, and seeing the mistakes is fun.
Dunno for how much longer they'll have them up, but one can stream entire episodes of McGoohan's masterwork on the AMC Web site right now.
If you want to go deeper into the series, Pmg6portmeirion and theprisonertv in particular has a massive number of bracingly engaging interviews with Patrick McGoohan and tons of behind-the-scenes material on their YouTube channels. I made a little playlist of a number of PM interviews and then music from the show.
If you prefer words with no pictures, here's BrokenSea's old-time-radio-style adaptation of the more-tolerated-than-authorized PRISONER comic-book sequel, SHATTERED IMAGE. I haven't fully experienced the results but it's an undeniably interesting experiment.