If that $2,500 is just your spare money then you are good to go with any of it depending on what's your crave and you know after conducting a research.
Basically with these questions I don't have to think about it as I'm about to say most of the time to invest and buy bitcoin. You don't have to think about it if you still don't have bitcoin but if you are an altcoin fan and you don't have a taste of bitcoin, why not take eth first?
I might suggest etherium and ripple. They are more popular and nore trusted kind of coins. They have higher value comparing to other coins next to bitcoin. They are weel known and great potentials to the world market.