Ethereum would be my option because i see a good future in it and you don't need a lot of money to buy it. On the other hand, bitcoin is quite expensive to buy and also kind of slow in their progress. So i think it would be more profitable if we invest in Ethereum.
Ehtereum is the future of smart contracts, and bitcoin is a good commodity if you ask this question to me. Both are counted as promising by the majority of the crypto people.