My most long gameplay is 50 hours, it's not enough for TES game.
122.22 hours into my first character. I've been playing him since release day, and not even close to finishing the game. Come to think of it, while I've completed a bunch of quests, I haven't finished one single questline. How's that for content
Want more gameplay than 50 hours? Quit abusing fast travel, Stop running everywhere you go. Roleplay your character. Don't try to do everything in one game. I've been to several dungeons more than once already because I had been out exploring and found that one, then the game sends me back to it for a quest.
Plenty of content to be had in Skyrim...if you want it. If you don't, I would then suggest that Skyrim isn't for you.