I'm going to be the outlier here and say W514. You will be able to find a really nice one for way less than your budget and it is 100+ years old. I *love* that it appears as though he is a member of the Red Sox, but says Yankees. I'd have to check my notes, but I think you could classify it as either his first Yankees card, last Red Sox card, or both, depending upon how you look at it.
The red sleeves leads me to believe that the artwork was done before the historic deal that changed baseball forever was finished, and produced afterward. To me, this card is a tangible piece of perhaps the biggest thing that has ever happened in baseball.
Oh, and for what it's worth, I really don't like strip cards all that much, but I LOVE the Ruth - I get gushy every time I look at it because of what it represents
Now, that said, the obvious choice that most everyone will say is a Goudey. I love those too, and have yet to bring one back into my collection. I think the reason that is, is because of my W514 fills the Ruth void quite nicely, though it is by far not his best or most expensive. That said, I would like a Goudey again soon