5. Lyle Talbot - Batman & Robin (1949)
Legendary character actor Lyle Talbot is notable as the first performer to portray Commissioner Gordon in live-action form, appearing as the character in 1949's 15-part Batman and Robin movie serial.
While Talbot's performance and the serial as a whole will seem positively quaint to modern audiences, the actor's hefty stature and velvety voice helped him bring real authority to the part, even if the serial is undeniably corny while lacking the wink-wink self-awareness of the Adam West series.
But Talbot sinks his teeth into the part with an admirable commitment far beyond the expected, introducing Jim Gordon to a mainstream audience far beyond the comics, and that's absolutely to be commended.
Fun fact: the very next year Talbot portrayed his second iconic DC character by playing Lex Luthor in the film serial Atom Man vs. Superman, a role which he clearly had a lot more fun with.