First introduced in Action Comics #1 way back in 1938 by Superman creators Jerry Siegel and Joe Shuster the character was based in part on 1930's fictional reporter Torchy Blane portrayed by actress Glenda Farrell. Headstrong and fearless to a fault, Lois would never compromise or give up on a story, even if it put her into enough danger to necessitate the Man of Steel bailing her out from time to time.
Over 70+ years in print, television, and films, Lois has gone through multiple reinterpretations and reboots. She even headlined her own comic book, Superman's Girl Friend, Lois Lane, for more than a decade. Over time she's been portrayed as everything from a damsel in distress to a Supeman's equal, and every variation in-between. Although other women in Superman's life have come and go, most notably Lana Lang, none have had the staying power of Lois who eventually married Clark in 1996 and the pair remained a a couple up until the New 52 reboot.
Several actors have provided the voice for Lois on radio and animation including Joan Alexander (for the original radio show and the Fleischer animated shorts from the 1940's), Shannon Farnon (on the Super Friends cartoons), and more recently Dana Delany (on Superman: The Animated Series and Justice League), and Anne Heche, Kyra Sedgwick, Christina Hendricks, Pauley Perrette, and Stana Katic in various recent DC animated movies.
In terms of live-action television and features Phyllis Coates played the role in The Adventures of Superman, Margot Kidder was Lois for an entire generation in all of the late 70's and 80's movies with Christopher Reeve, Kate Bosworth took over the role in Superman Returns, Amy Adams played Lois in Man of Steel, and Erica Durance was brought in to play a younger version of the character on Smallville. However, my personal favorite was Teri Hatcher's hard-driven but goofy take on the character in Lois & Clark: The New Adventures of Superman. Hatcher gave us a Lois with beauty and brains who wasn't afraid to show her insecurities (at least to the audience) and was a fitting match for the last son of Krypton.
Whoever your favorite version is, in television, movies, or in print, one thing is for sure: Lois Lane has made a lasting name for herself as far more than just Superman's Girl Friday. Strong, independent, smart, savvy, bull-headed, and at times even a little too reckless for her own good, and that's what makes her an awesome character.