personally, i LOVE swain. he's an AP sustain mage, that deals tons of damage, but has really good healing and 2 forms of cc (root and a draw-in) and he is sort of basic to learn as well.
but for general list of people, here's what i think
(essentailly a sustain god)
(he just does way too much frekin damage and hes very tanky as well)
(great against AP heavy teams, and you can build him pseudo tanky and he can dish out some good damage all while tanking up some good stuff)
(do i even need to explain him....)
(just.....beyond broken and tanky)
(can dish out really good damage and has high mobility, and has some really good sustain with items, along side a 50% damage reduction W)
(Rhaast.)
(farm this puppy up...just...one shot everyone)
(really good damage and can take a good hit or 2)
(absurd damage with his EW passive Q combo, and his ult gives him extra temporary HP and allows for some really good sustain, combine it with zhonyas and spirit visage, zhonyas in the middle of the team and get back all of your hp)
(whole kit revolves around HP pretty much. Q steals and recovers HP, E uses set amount of HP as damage, R recovers a whole ton of HP, and the more HP you have the more AP you get and the more AP you have the more HP you get (doesnt stack with each other tho)
(hes has suprisingly good sustain and does really good damage along with a execute ult)
(its warwick...the god of heals....)
(can be built tank, and can deal a really good amount of damage the more missing HP the opponet has)
(love splitpushing forever? love high damage? love being naturally tanky? yorick is pretty good)
these are just a few i can think of off the top of my head that are pretty decent. i dont play any of them only like 2 or 3 of them listed, but basically Juggernauts, Divers, and a few Wardens are in this rage imo