Ret paladins are imo in a league of their own in this bracket, insane burst, defensives and self healing of tanks and you have to kill one 3-4 times inbetween their bubbles before they actually die. To top it off they have been dumbed down even more in BFA, so they will kill you with 3 buttons with mostly no counterplay. Very frustrating for the recieveing end.
For topping the damage charts if that is your thing, the usual dot classes perform the best as usual. Boomkins, spriests and afflocks. That beeing said, since you can reach comfortable levels on secondary stats in this bracket, pretty much anything can be fun to play. Even holy priests can do well here.
If you are rolling EU I would personally suggest going horde if you want a challenge. Alliance have a huge 110 community that does bg-premades every day, but gy-camping for 15 minutes every bg (if you are a part of those premades) is not my cup of tea, so I am only playing horde myself now and having a lot more fun even if we don't win every bg (you can really outperform alliance teams with 5-7 twinks). There is also a lot of bad seeds in the alliance community, but if you like to soloqueue both sides work well with decent queues on both sides.