So, let me say right away that I am not telling you that these superheroes would beat Deadpool in a fight or that you should like them more (because I know you likely are only reading this because it has Deadpool in the title), rather just that I think they are most interesting and well-developed characters.

So, keep that in mind. Here we go:

1. Wiccan (William Kaplan) - William "Billy" Kaplan is a mutant child of Scarlet Witch and the Vision and he possesses the power to warp reality through his Chaos Magic. He first was introduced in the original Young Avengers title where he patterned himself after the Asgardian God and superhero, Thor. Wiccan has become very well versed in his spell-casting abilities and is debatably one of the most powerful sorcerers in the Marvel universe. Now Wiccan fights crime alongside with other heroes in a team called The New Avengers.

2. X-23 (Laura Kinney) - Laura was created as a female clone (or daughter, depending on who you ask) of Wolverine and possesses a similar healing factor and has similar claws (she has 2 in her hands and one in her foot). Aside from these mutant abilities, she also has had intensive training in martial arts while she lived in captivity as an assassin. After James "Logan" Howlett died, Laura took over as the All New Wolverine.

3. Captain Marvel (Carol Danvers) - Carol Danvers' DNA was altered by an explosion, where an alien Kree hero (the original Captain Marvel) saved her and their DNA fused together. This caused Carol Danvers to gain superhuman strength, stamina, flight, physical durability, and energy absorption (as well as a few other, semi-unacknowledged abilities). Using these abilities, she began fighting crime under the name Ms. Marvel, and after Captain Marvel's death, she took over with his name.

4. Magik (Illyana Rasputin) - Sister of the well-known x-man, Colossus, Illyana has the mutant ability to teleport. She uses a dimension called Limbo as a midway point to enable her to teleport at great lengths; Magik was raised in Limbo and eventually became the Sorcerer Supreme of that dimension, due to her near-limitless sorceress abilities while there (however, on Earth, these sorcery powers were hindered).

5. Agent Venom (Flash Thompson) - Flash Thompson was a highschool bully who went into the military and lost his legs during his service. After the military, he is offered a militarized version of the venom symbiote (a dangerous gooey biotic mass) which would be able to make new usable legs for Flash from it's biomass. Flash began fighting crime using the powerful symbiote to his advantage. He currently is fighting with the Guardians of the Galaxy throughout the Marvel universe.