For Jungle you should try out Nautilus if you don't already play him. His CC is amazing in securing ganks so long as your team follows up. ADC I am a fan of Graves and Ashe. Mid I am a huge fan of Lux, but she takes alot of practice to get used to in the world of mobility.
I think the easiest champ is annie , she has 2 line description skills and and she is pretty straightforward to play not to mention she has no skill shots and she can do well even without items through her cc, I will make a sum of what her abilities do:
Q: throw fire to the selected enemy. W: throw fire in front of you. E: envelope your self with a fire shield that shouldn't bother reading its description as you can have it on 90% of the time, R: throw a fire bear in the selected position
And here is all the disciocion making and mechanic knowledge a annie player needs to have in order to do well :
you have stun on ? -> flash ult those squishes from 100 to 0. if they din't die , just spam your 80% ap ratio, 3 second cooldown abilities
I try not to play easy champions but I think all the champions I play are super fun :]
- Both top and mid, this guy is great once you learn how to play him. Laning can be tricky but if you can position well his teamfight is amazing.
- I play her mid when Azir gets banned or picked from me. She's a really strong lane bully with tons of pick potential and mobility. Really fun to play!
- My go-to ADC. Not the greatest duelist but you can easily shove waves and your teamfight is incredible. Lots of poke and great for catching people out of position.
- When I have to support I usually play this. It's really fun to manage your seeds and you're a pretty big lane bully after level 2 with your QW harass since it doesn't cost a whole lot of money and does pretty much guaranteed damage due to the plant. Late game your ult is awesome for teamfights and you do a lot of damage even without items due to high bases!
I try to avoid top and jungle when I can (unless it's my Azir top). I'm just not a fan of tanky bruisers and frontline champions and that seems to be what everyone wants out of a top/jungle player.
Jungle-Evelynn and Kha Zic because they have great ganks but require some thinking on how to approach them. Support-Thresh Morgana and Nautilus Mid lane-Ahri Azir Top-Rumble Gnar Maokai I do not play ADC
I've been messing around with 
as a melee adc, and it's funny. Given a support or Naut/Voli/Tahm, you have pretty good trades that couple into amazing all-ins post-6. Though I recommend being good with yasuo mechanically, since putting him in bot lane requires a lot more skill than having him in mid.
There's also jungle Ekko. He can be played as either a full tank or as an AP assassin jungle, so you could try him if you haven't.
A good champion to play for mid adc or jungle is ahri she is easy to play and lots of fun.Plus she is hard to kill and her kiss ability allows her to escape or to help a team mate escape when their health is low.I hope this helps give her a try.
Ahri, Azir, Ezreal, Akali, off the top of my head.
Almost forgot morgana.
Bard is a ton of fun to play even if you don't get the hang of him for awhile. Probably one of the funnest in league right now.
I mean, even jungling with him is great fun. It's hard to go wrong with Bard!
For Mid play 
.
If no one buys 
you will crap on anyone.
He's easy and fun.
simple and super fun to play imo
