I think Bitcoin has the longest proven record of all cryptocurrencies by virtue of being the very first. It's also accepted at the most outlets, and its support across the globe is strongest. When it comes to name recognition too, there is no denying that Bitcoin is the most visible. Bitcoin is still the best store of value. It's well recognized, supported by almost all cryptocurrency services, and has a longer history.
Litecoin is one of the better alt-coins when it comes to storing value, however, so it's a good pick if you're looking to try out a different currency.
Even if Bitcoin is stronger as a way of storing value over time, Litecoin clearly has the edge in transferring wealth as payments and transactions. That shouldn't be too much of a surprise, as that was the original purpose of the cryptocurrency.