Hate:
Lazy UI porting between PC and console. It goes both ways - radial menus showing up in a PC game or a joystick-controlled-cursor in a console game. M+KB vs controller are not comparable input methods, so trying to manage the UI with one that was built for the other is always a massive pain in the ass.
Inventory restrictions in games that throw a LOT of shit your way. Looking at you, Bethesda. Fortunately there's usually a mod of some kind to make items weigh like 0.01 lbs, or kick your slots up to 9999 or something. Sometimes realism adds to the experience... inventory management isn't one of those times.
Sluggish controls. I want to actually enjoy the Dark Souls games SO BAD - they look beautiful, I fuckin love that dark fantasy setting... but moving and combat feel like I'm driving a school bus with boxing gloves on my hands and diving flippers on my feet. I get that the cumbersome controls are a huge part of what makes it difficult, and that the difficulty is what a lot of players are after, but personally that's not a flavor of difficulty I'll ever be able to enjoy.
Love:
Good QOL features, especially involving the topics above. Like 'Hot Deposit' certain items to all designated storages in range, or AoE loot when a bunch of foes die in a pile. The quick loot style menu from Fallout 4 is another great example. Love that stuff!
Lore. Good story writing, believable/relatable characters, ESPECIALLY the antagonists. Hitting the sweet spot there is a quick ticket to my all time favorites.
Environmental challenges, with fun ways to overcome them. When I was new to Ark, one of the biggest challenges in my first play through was getting into the super cold zones and not freezing to death. My cold weather gear didn't cut it... the solution I came up with was to tame a paracer (kind of an elephant looking dino) and build a platform on its back: and made like 6 camp fires on the platform. So the I was, trudging through an insanely cold environment on a flaming elephant, cozy as can be. As a veteran player now, there are SO much more efficient methods to solving that problem, but the experience gave a unique sense of accomplishment, which is the kind of thing that got me hooked on that game.
Escorts matching the move speed of the player. 'nuff said.