Because you like Leonard "Bones" McCoy in Star Trek
Part archaeologist, part philosopher, part politician, Jean-Luc Picard is an unashamed intellectual who runs a tight ship. See them in Star Trek: The Next Generation.
This android may not have emotions, but Lt. Commander Data's curiosity about humanity is endless. See them in Star Trek: The Next Generation.
Khan Noonien Singh is super strong, super smart, and out for revenge. He always seems to be two steps ahead of his enemies. See them in Star Trek Into Darkness.
K-2SO is a blunt and sarcastic reprogrammed Imperial droid who is always up for an adventure. See them in Rogue One.
James Gordon happens to be the one guy in Gotham City with proper morals who doesn't also run around in a cape. See them in DC Extended Universe.
Despite the war-torn world around him, Mal Reynolds still holds onto the shred of hope that life can be more than just living another day. See them in Firefly.
Rupert Giles is a librarian on the outside, fearless evil-fighter on the inside. See them in Buffy the Vampire Slayer.
Cyclops shoots lasers out of his eyes, destroying anything in his line of sight. See them in X-Men Series.
Sarcastic and always complaining, C3PO is a droid that despite his quirks you always want by your side. See them in Star Wars Series.
Hank McCoy is a quintessential nerdy scientist but with a few rather unconventional physical attributes. See them in X-Men Series.
A compassionate medical student, Martha Jones has found a Doctor she can really look up to. See them in Doctor Who.