Ok so I will start with Marvel 1st.
Marvel is the home to my famous superheroes including:
Spiderman
Wolverine
Hulk
Captain America
Mr. Fantastic
Storm
Thor
Iron Man
Ghost Rider
The Invisible Girl
Deadpool
and countless others
There are also many groups of heroes in the Marvel Universe including:
The X-Men
The Avengers
The Fantastic Four (which later became the Fantastic Five)
Marvel Knights
The Marvel Universe is so great that I think instead of spending hours going into details about each hero, I will let you go look at them for you self
Here's a link to help with that:
http://marvel.com/universe/Main_Page
Now onto DC.
DC (also know as Detective Comics) has many well know superheroes including:
Batman
Superman
Wonder Woman
Nightwing
Green Lantern
Flash
Aquaman
Blue Beetle
and many others
There are also multiple hero groups including:
The Teen Titans
Justice League of America
The Outsiders
and many more.
For more info on DC superheroes try going to:
http://www.dccomics.com/dcu/
but I do not know how much info you will get.
Well I hope I helped you either appreciate comics more or pick a side. Have fun reading more comics!