The struggle of finding a long-term enjoyable champion

I've been playing League since season 2 (granted with many long breaks or inactive periods in-between) and one thing that I've always struggled with during these years was finding a champion that would just stick with me.

I've asked on the old Forums, these Boards, lots of people or friends on how they found a champion they simply prefer over others and it was all usually answered with not having looked for them, but simply trying them out and liking them.

It's what I've been doing too, if a champion's playstyle seemed to be ok, I'd give them a try and there were many over the years that I've simply enjoyed playing and felt like I wanted to invest time in them.

So that's what I'd always do, and what I'm still doing, yet after a set number of games I'd simply get bored of them. It's always a similar laning patterns with minimal differences based on matchup, enemy jungler, first few levels and so on, but it does always feel like I'm playing the same game.

Some of the recent ones and how I've felt on them:

Veigar - Simply farm minions with Q, harass with Q, start to one-shot after Luden's, basically during the whole game. Vel'Koz - Poke with Q, clear with W, land a good Q-E and you get yourself a kill, basically during the whole game. Viktor - Harass at lv1-3 then try to farm the manaflow and 1150G for your first upgrade, from there it becomes all about waveclear, one-shots after lich bane and worry about landing a good W-R in teamfights, basically during the whole game. Xerath - Poke... basically during the whole game. Malzahar - Either E minions and Q-W to clear or E a champion and Q for damage, R when necessary, basically during the whole game.

While these playstyles are all something I like, I don't know how to make them feel less repetitive. This is honestly applicable to every champion I've enjoyed playing ever since Season 2, that I feel like I'm always doing the same thing every game, with very very minimal difference.

I guess this is just meant to be a rant on how I feel like the reason I always end up ditching League for an extended period of time is due to this. I find a nice champion that sits with me, I start playing it more, I get reasonably good at it, then I simply get bored of the repetition. Anyone else can relate to this process?