Here are the genres that are loosely related to screamo, with 2 bands from each genre;
Screamo:
Alesana
A Skylit Drive
Post-Hardcore:
Escape the Fate
Asking Alexandria
Hardcore:
The Great Commission
Full Blown Chaos
Metalcore:
Parkway Drive
UnderOATH
Deathcore:
Job for a Cowboy
Whitechapel
Death Metal:
Impending Doom
The Black Dahlia Murder
Melodeath Metal (melodic):
In Flames
Destroy Destroy Destroy
Electrocore:
We Came as Romans
My Sky Your City
Grindcore:
Napalm Death
The Red Chord
Crunkcore:
Dotdotcurve
Brokencyde
Noise Grind:
Waking the Cadaver
Annotations of an Autopsy (Also kinda deathcore)
Gore Grind (porno grind):
Cannibal Corpse
a**l c**t