Noob here who wants to play multiplayer- AoE II HD the way to go?

Hi guys,

After watching Spirit of the Law's great videos on youtube, he really made me interested in playing AoE on multiplayer.

I have 3 questions

1) Is AoE 2 HD the most played AoE game? Or should you go for AoE3 or something? 2) Do you need all the expansions to get a good game? Base game is 20 Euros on steam, but game and expansions is 40 euros. 3) How do you get to play vs ranked opponents? I'd like a system similar to Starcraft 2, where you search for a standard game and get matched with an opponent of similar skill. Is this how it works in AoE?

Thanks!