If I had the choice to buy only one of the two today, I guess it would be monero. Even if I personally think that LTC is better as a coin than monero, I know that monero has more potential to grow in the future than LTC. Also LTC is a bit overpriced right now, while monero is still underpriced and therefore, has a big chance to pump sooner or later this year. I would consider changing choices if ltc dumps like crazy now.