Party of two

You're preparing to play in a mid-level 5E "D&D" campaign. There is one other player. The DM tells you that the coming adventures will require a wide variety of abilities. However, she does not allow multi-class or non-standard characters in her game. You and your fellow player must now decide which combo of classes will give your party - such as it is - maximum versatility and hence maximum chance of success. Which two do you choose?

My heart says Ranger and Druid, just because it's a natural pairing I've always liked. Given that we're talking 5E, though, my head tells me there's probably a much trickier combination to be had, e.g. War Domain Cleric and Arcane Trickster Rogue. 

Feel free to share your thoughts on the matter in the comments. Oh, and if your instinctive response to the first paragraph above was, "Just hire some NPCs," then congratulations - you win the Lateral Thinking Award :-)