My mum's pretty easy but my Dad is a nightmare to the point where I've refused (but then gone back on it) to buy him presents more than a few years.
Both of them are sadly pretty sedentary and their main activity after work is watching TV. They often go out to a local pub for a meal but only because they go there so often they have £££ in reward vouchers so it's a cheap meal for them. My mum is into crafting, knitting and gardening but now has a very small garden and a bedroom full of craft stuff, so it's pointless buying her any of that. She does read though so she'll often get a book that looks interesting (though prefers to read on her kindle).
My Dad however. His hobbies are - arguing on twitter - going to support his non league football club (two matches a week in season and a board meeting once a week all year round, fortnightly pub drinks with the committee) - going to support his premiership football team when his team isn't playing. He buys everything for himself. He has stacks of gifts given to him piled next to his bed because he doesn't do anything with them. Doesn't read books. Likes beer and chocolate/nice food but if I'm honest it worries me buying him stuff like that because like I said they're both very sedentary and getting to an age where their weight is going to impact their health significantly. Gets 1 new pair of slippers every year but wants nothing else and will suggest nothing else. Has all the football memorabilia you could imagine. Doesn't like any other hobbies, sports or activities.