Game with challenging dungeons and PvP?

Hi, me and two other friends were looking for an mmo to get into and those two things would he our main requirements. We want to get into some fun group content (preferably on the smaller scale so it's mostly us but not too big of a deal) and also have the option to pvp when we're feeling competitive.

Which game would fit that best? And how long would it take to reach the point where we can do those things most of the time?