What I've often found is that people find gifts that "work" and they fall back on those when they don't know what the person actually wants. We often have this expectation that all of our friends and family should know what we want for our birthday or the holidays without them asking or without us telling them. The idea, "you're my parent/spouse/sibling/grandparent; I shouldn't need to tell you what I want, it should be obvious!" is a sweet thought but it's often not realistic.
So, to help combat this, make it obvious what you want. Rather than focusing on what you don't want, tell them what you do... make a wishlist (for example, on Amazon), tell them,
This year, I really would like ties. I find that I'm bored with the ones I have and I'd love some that were really colorful.
You can be general or specific, depending on your preferences and level of comfort. Yes, I know that in some groups telling people "give me this" can look crass, but there are ways of being more subtle and then there are some family members (like my Mother-in-Law) who will find it amazing to be able to actually get you something you want and will insist that you keep your wishlist full of options all the time. This is how she knows what to buy for myself, my husband, and our son and it means we get gifts we actually want... and since she has one, too... we're able to do the same thing. Everyone comes away happy in the end.
It may be a bit uncomfortable at first but it can really be a great way for your family to really start giving things you want (or need!) that doesn't turn into [unenthusiastic] "Oh, yay... socks, again... Thanks, mama."
Now, this becomes a bit of a "lead a horse to water" issue, at times... sometimes, telling people what you want won't always get it for you. You'll keep getting socks. At that point, you may need to either sit down with them and explain why socks are a bad gift for you and why it's a waste of their money to give you socks or decide that you're going to just let it go.
Hey dad, I know you really like getting me socks for my birthday and I really appreciate that you think of me and try to get something I like... but here's a photo of my current collection of socks. As you can see, I have a lot of them and, to be honest, I very rarely use socks. I'm happy to let you know what I'd like instead (ties) and if you're really a fan of giving me socks, you can... but you should realize that I don't really need them or use them. If that changes, I'll let you know, though!
So, here you're showing appreciation, explaining the problem, giving them a solution and telling them that if you decide you need socks again sometime, you'll let them know. Hopefully this should put an end to socks without hurting any feelings. They may even tell you
Wow, I didn't realize! You should have said something sooner! I thought you really loved socks, so that's why I've been giving them to you this whole time.