Higgins, I propose this question to you: Why pick other heroes when you have D.Va??? She's amazing. I don't know why some people here poop on her. There are a few times where she's not ideal for some context, but she's a crazy good all around hero. She wallops on heroes close-range, she has the beef and multiple abilities that let her close that range, excellent mobility so you can avoid shitty situations, and if she dies she basically has a second life. And she's secretly amazing out of her mech too, because her gun has excellent range, pin-point accuracy, and hits really really hard. There are times I've done strafing outside a door, just shot a continuous stream of bullets inside, and eventually killed people who popped their heads out that way. Or times where a bastion gets set up, and I poke my head out just enough to see his foot but he can't see me, and then I send a full clip at that food and poof - bastion is dead and can't figure out how until his deathcam. There's been plenty of times where I could have called down a new mech and put it off for quite a while because "nah, I'd rather keep going at dudes long range". I do think she's kinda shitty at escort/payload missions, but that's about it. And even then, charging up and using her ult at the right time, even if you don't kill anyone, can create enough space for your team to push that cart (or stop it) just enough to get it over a checkpoint. And she's *very* misplaced as a 'tank' IMO (she's more an attacker) but if you pocket her defense matrix instead of using it offensively, it can save your whole team from a wipe if you time it right against some of the most devastating room-clearing ults in the game (like mccree's, pharah's, reaper's, bastion's, etc). In short, D.Va is bae. I've gotten to the point where I can pull gold medals out of my ass with her on a pretty regular basis for offensive things, it's great.
Higgins, you might also like Mei, because she doesn't really require a lot of twitch reflex to be useful to your team, and she's a massive dickhead when it comes to disrupting the enemy team, and she's hard to kill too because of her get-out-of-jail-free card. Mei is the ultimate troll character, it's kind of amazing how good she is.