Reading Suicide Squad you expect the clash of outlandish personalities, ultra-violence, a healthy amount of snark, and inner-team rivalry, but the book took off because it went political, explicitly exploring the real-world consequences of superheroes incorporating the real-world politics of the time. The Squad's relatively unknown staples -- Deadshot, Captain Boomerang, Enchantress, Slipknot -- run the walk-of-life gamut. Daddy issues, dead wives, masochism, domestic violence, amnesia -- you name it, someone on the team's been screwed up by it. Suicide Squad stories are thrilling, intense forays into the deepest corners of the DC Universe.
The Squad is inclusive to all evil-doers (almost)
Since Ostrander's '80s update, the Suicide Squad has had a revolving door for members of DC's rogue gallery. I can't list every villain to have ever walked through the Squad (do you have a week?) but Poison Ivy, Bronze Tiger, Plastique, Killer Frost, Black Manta, Reverse-Flash, and Cheetah all stopped by for a mission or two. Apologies to Angle Man, who never made the cut.