The CW's Arrowverse - comprised of Arrow, The Flash, Legends of Tomorrow and Supergirl (plus, Constantine and Vixen) - has given us plenty of great characters over the years.
Most of these had the bedrock of being based off a character who was already awesome in the world of DC comics. For instance, Barry Allen's Flash, Green Arrow, Martian Manhunter and many more. Alternatively, others were completely original creations (Alex Danvers, Joe West, John Diggle etc), which meant they weren't held back by any baggage.
Some characters, however, were adaptations of those who actually weren't so great in the comic book universe. Be they a forgotten footnote in superhero history, a character usually left in the background, or just someone who was plain rubbish, these guys didn't make a whole lot of impact on the page.
Whatever their origins, the Arrowverse has had the honour of saving these characters and making them popular, fully-characterized people. Some of the following characters might not be your personal favourites, but - whether they are a supporting character, a season-long villain or even the star of the show - you have to admit they are stronger than they were in the comics.