Perhaps this is an unpopular opinion, but I seriously can't deal with Darius...
He's tanky af. He has heals. He has decent crowd control. He has INCREDIBLE damage (Q hurts, W hurts, passive armor pen on E, the fkin hemorrhage stacks, and then the MASSIVE AD buff when he gets 5 stacks...O ya, and his ~1000 TRUE DAMAGE ultimate that HAS NO COOLDOWN). And before you tell me "well he's easily kiteable, he has no gapcloser, etc" well, here's the thing:
gives movement speed buff for stickiness (and his passive refreshes this while shredding armor) and
gives him that bit of bonus speed to get into a fight and start wreaking havoc. Also, I'm seeing more and more of them build
. You simply cannot run from this, if he manages to hit you, you HAVE to flash or burn some other kind of escape ability.

it's pretty easy to trade with her or zone her... and eventually all in her.
, the attack speed slow does wonders on him. Sustain isn't necessary, but recommended. Also no
, he's garbage, period.
are all primary top laners I would say can snowball as hard as or harder than Darius. Maybe not as easily since most of them have been nerfed pretty heavily for that exact reason, but they've definitely been able to run away with the game in the past.
or
as soon as you can and if you're melee, stand close to him so he doesn't get the heal at all. Picking a champion with high % damage works wonders too, like
for jungling or
top; if you don't, you should build a BotRK (assuming you want to duel him and aren't a tank.)
I Spin2Win into him, hitting W to block most of his burst, then Q and disengage while He's silenced so he can't pull me back. I repeat until he's low, then