The best suggestion here is to invest in Doge. It would be weird to make other suggestions in the Doge community. If you want to diversify, you can have a look at several coins and ico's that seem to be doing nicely. One way is to look at the top 20 coins on coinmarketcap, based on market cap (price per coin * number of coins in existence) but the real gems are under appreciated coins that will be discovered soon and might have a big growth. Remember: there is no guarantee that any coin will rise in value or even survive the next 6 months.
It's only a good time to invest in doge and keep them , the coin hasn't reach the full main stream . i remember back in 2014 when i had doge on a casino and if you had much on invest you would have made a really nice profit to be honest.