I have farmed from champ 1 to silver 3 in the last month. I am Th10, all buildings maxed, all troops maxed, BK35, AQ31 (32 tomorrow), about 170 lava.
imo the length of your sessions is the key determiner in the most suitable league for you. The shorter your sessions the lower the league. My sessions are very short = 1 storage raid with 1 or 2 collector grabs on the way while i'm nexting, so silver is ideal for me. I had problems saving 160k dark in champ because i only do 1 full raid Each time i log on.
If you farm in sessions and like winning the loot bonus farm in champ 3.
If you farm casually farm in silver or gold. Curiously i find more abandoned bases in gold, but also more bases with no loot. In silver the loot is always steady. Plenty of TH10s and TH9s with max storage loot available and quite a few easy bases with full mines/collectors/drills.
With the new matchmaking system farming as TH10 is easy in any league. Loot is similar in all leagues, and imo profits/day are similar in all leagues. You get high loot bonuses in high leagues but generally you next more and you use full armies, more expensive troops and spells. in low leagues i often do 2-3 quick raids using only half my army which gives as much loot as one huge raid plus huge loot bonus in champ.
I find silver the most relaxing :
- I never lose ANY loot when i log off which is great when u have max avail DE for days on end while waiting for hero to finish upgrade.
- I can log on, do a single raid or a couple of quick raids, log off and know that everything i raid stays in my storages.
I find silver the easiest :
- Very little nexting cause i can go for almost any base using a hybrid army - half giant/wb/gobs to go for central storages and half BAM to go for full collectors/mines/drills.
- And lots of easy targets - there are plenty of TH9s here.
I'm raiding every hour or 2, doing 25-30k dark and several mill gold and elixir/day. Absolutely no problems finding dark here. I upgraded haste spell lvl 4 for 100k dark 10 days ago, queen lvl 32 for 155k dark 6 days ago and i have almost full dark storage again now. Doing queen lvl 33 tomorrow.
Planning to get my queen to 35 over the next 3 weeks. Then do the push in Nov with forum elite, and then decide whether i come back to silver to max my heros or stay in high champ/titan to do the last 5 levels of each hero. I haven't farmed in titan but the guys who were in titan in my last push clan in august said then that the loot was Pretty good in titan 3.
Good luck. choose the league that suits your coc style. You will make the same loot in any leqgue. best leqgue for you depends on how much you want to invest (in your armies and of your time), how much loot you are prepared to lose and how much you care about trophies and/or winning battles.