I'm pretty new to this, and after researching a bit, I feel like ETH is going places and has far fewer barriers to expansion that BTC. I want to buy and hold some coins, and as of now i'm leaning towards ETH. but I can't ignore the fact that bitcoin seems like top dog still... so convince me to buy BTC instead of eth. Give a reason besides "first movers advantage" 
I like both. Bitcoin is most trusted coin all over world. And bitcoin is the first/main of cryotocurrency.
You can exchange any other currency via bitcoin. But you can't covert via Eth to any other, such as skrill, paypal etc.
You can invest easily via bitcoin.