Im all for both. I mean.. I suppose I am more for character building, questing, and such than I am straight up leveling up.. but I think there's gotta be both in there. I get all greedy seeing abilities and such that I COULD have.
Taking a few classic favorites of mine..
Final Fantasy tends to run a good amount of storyline, shiny stuff, quests, world-building, and leveling. I consider leveling part of character development as well though.
Diablo was more dungeon crawlers.. a few quests, with a LOT of killing involved in each... but I was equally happy. The leveling gave me all sorts of new interesting things to use and try out, so I didn't get tired of it.
What I DONT like is Phantasy Star sort of games.. where it's just run into here, kill everything, and then do THE SAME THING AGAIN. I don't mind having to re-do a level because I Personally want something.. but straight up repeating shit tires me of something really quickly.
I like games that let you choose.. Like Taking Kingdom Hearts for example: You don't have to do ANY of the side quests, leveling, or anything to get to the end and potentially beat the game if you're stuck on story. If you want everything, you can struggle for that as well.
I was also a fan of Tomb Raider games.. which involved no leveling up at all, simply solving riddles and shooting a few things.
But sometimes, Yes. I just want to go in, and beat up a lot of shit mindlessly. Sometimes that is just pure enjoyable when you don't have to do any thinking at all.