I'm ready for the downvotes
I'd take the toxic/good player if im in ranked.
The nice/bad player tilts me a bit more.
Im thinking of real situations ive had. I've seen some of the friendliest people in the game single-handedly lose me a game. Hard. At that point, you're not really trying to win. Climbing is not a thing.
When riot's popularity is grossly based on competition and promoting competition; it fees a bit unfair when they do a 180 and say "its only a game; just be merry and lose. Being good isnt a big deal". Like, well some people want to be good and try hard in ranked games and want to see the fruits of their labor.
For me, getting the friendly/bad player is like getting a drunk player on my team. They may be fun and happy, but you know you're going to lose.
If im playing a friendly game; no problem. If im playing a game to win; i'd love to see some people actually try on my team.
If im being 100% honest, I'd take the toxic/good player. I'll admit; maybe thats not a healthy perspective about a game lol. I kinda wish I really didn't care too much a bout my rank. I meany why? It is just a game. You'd never hear riot promote it as such, but it is. Can you imagine their next marketing campaign? XD "DW its just a game. You don't have to be good. Just have fun."
Ask any pro player in a pro game (maybe even some important promos) who'd they rather have; a friendly/bad player or a toxic/good player.
To elaborate a friendly/bad playing im saying you're pretty much 4v6. Like the player is feeding their entire team, building the worst build ever on their champion, and basically drunk. I can mute or ignore people too verbal in chat. The worst of toxicity I've experienced is somebody pinging too much. Usually (not always) if I tell them to stop they do. So im basing this on what I've personally experienced from either camp.