Hard to say really. I think as long as you give something that isn't TOO personalized (without knowing for certain that it is exactly what the person wants) and it fits them then it can be great. Big or small. Nobody wants trinkets for their decor that they didn't choose themselves. They just don't. I'll decorate my own space, thanks.
But since we love coffee.. any coffee bean gift is welcomed. Or coffee mugs. Or coffee gift cards to a place we get get coffee. (Can we afford coffee out ourselves? yes. But it makes it a treat and guilt free when you splurge on the thing you normally wouldn't buy---the larger one, or the one with the extra shots of espresso maybe, or just on the way into work when you'd normally make it at home during the week.)
If you are a reader... good books. Or bookstore cards (same reason--yes, can afford to buy whichever books we want--but it 's guilt free-no thinking "I should be spending this on XXX.")
If you like wine or mixed drinks... never can go wrong with a decent bottle of something you know they like. If you know the type but not a particular bottle--go to a wine store and ASK.
Now that we are all grown ups (seriously, around 50--all the siblings), I don't need or want you guessing what sweater I'll wear, or what size, etc. A nice $10-15 bottle of a wine you know I enjoy or think I might enjoy based on my tastes is fabulous! I can experiment without worrying I've wasted $.
Mom gave me some decorative smelly seashell stuff this year. (why? It doesn't even match my decor at all.) But she also made my husband and me a quilt. MADE. Hand quilted on a quilt frame. LOVE!
I have young adult nieces who are mostly independent now. While we don't go overboard, I think it's nice to give them perks... ChikFila A calendar (with the calendar card that gives them one free item each month of the year) and a Starbucks card with enough $ loaded on it for 2-3 drinks (not plain coffee). It doesn't break the bank, and it isn't a poor guess about clothing tastes or musical tastes, or duplicating a gift concerns. They are nice little perks to brighten their day here or there next month (or once a month all year).
I like perfume I like and husband is pretty good at figuring out what scents suit me. But I am NOT a fan of the gift SETS that come with body wash or lotion in them as well. It's too much and I don't tend to ever use those parts of the set. They are a waste.
Best gift ever? Well, that's pretty tough... I'll go sappy and say hearing my teen kids playing a game at the breakfast table and one says, "We have to play it again! No, we're not done... I'm going to win this next one. Best 2 out of 3!"