@Doombreed and @SirLegendary How are they similar? There's some minor costume similarities but otherwise they're completely different characters. Deathstroke is a peak human bounty hunter with slightly superhuman regeneration (depending on the writer, sometimes he goes full blown Wolverine) and a lot of martial arts skills. The closest Marvel villain to him is Taskmaster. Deadpool on the other hand is a comedic mercenary who breaks the fourth wall and whose regeneration significantly outclasses any other character in in the DC or Marvel universe with the exception of Pre-Crisis Lobo. Aside from the grim nature of his work and origin Deadpool is closer to the Looney Tunes than Deathstroke.
@Ishtaron they pretty much use the same weapons, both have regenerative abilities, both were ex-soldiers and the one's name is Wade Wilson and the other one's name is (or was at least for some time) Slade Wilson. I mean come on!
@Doombreed Unless they're using some kind of gimmick, every bounty hunter or mercenary from every universe uses the same weapons. Blades and guns are basically the only practical weapons out there unless you're Bruce Wayne levels of rich and can spend billions on bat shaped toys. Other characters that use such weapons include: Red Hood, Han Solo, The Punisher, Black Widow (with some less conventional extras courtesy of SHIELD), almost every character in One Piece that doesn't have a devil fruit, etc. etc. etc.
Regeneration is also hardly uncommon. Wolverine is the source of Deadpool's and X-23's regenerative abilities. Sabretooth, Lobo, Superman, Braniac,The Flash, Crocodile, Reptile, and a host of others also have regeneration superpowers. Even characters in Fallout can gain regenerative abilities thanks to the Solar Powered perk and/or a PHOENIX implant in New Vegas.
Basically, the only uncanny similarity between them is their names and even that can be chocked up to lazy writers. Personality-wise they're complete opposites. Even their history isn't all that similar. Wade is a Canadian who joined the military after a friend killed his abusive father, then he started taking assassination jobs but only if he felt the target deserved to die. Slade was an American patriot trying to join the war who quickly returned and married a woman he met while in the army.
Uhm yes Deathstroke was a primary influence for Deadpool. The guy who originally Made Deadpool showed another guy who said "This looks like Deathstroke." To which he responded "Hey it does!" So as a joke they named Deadpool Wade Wilson (A play on Slade Wilson). But I always liked Batman, not the crappy movie Batman either. My favorite though is tough to say, probably Joker.
I just watched something recently, and I think Deahstroke should be more popular than Deadpool.
Haha, good one.
Deathstroke is awesome. He is a likeable villain who kicks butts and stuff, but Deadpool with forever be better. He's more unique oddly enough due to him starting as a copycat of Deathstroke. Either way, Deadpool brings more to the table. While he does not have that realistic and gritty sense that a character like Deathstroke brings (which is awesome too), Deadpool is something uniquely special. The silly-ness of the problems Wade finds himself in and the hilarious writing make him stand out more, which is why he's more popular.
Deathstroke is a great character and all, but he's essentially an evil version of Batman with a few buffs, while a Deadpool comic is something completely hilarious, ridiculous, and unique.
Wade > Slade
Anyways, my favorite DC character changes between Batman and Flash depending on what I've read/watched/played recently. At the moment it seems like Flash. Shazam comes in at a solid third place.
And I kinda have a separate list for villains too which at the moment consists of Captain Cold, Scarecrow, and Deahtstroke ironically.