This is more a garden with wisely organized viewpoints rather than an open-air museum. Pity is that the prevailing part of the visitors have absolutely no clue what was here, what are the brick structures around and why they are visiting the Palatine themselves in first place. Massive guided tours in all possible languages just ruin single tourist intentions and impressions (but this true for entire Rome and especially in the summer). In fact this hill is the root from which Rome grew. The Lupercal was here, once we spent decent amount of time with kids lookin for it :) Romans prayed to No-named God exactly on this hill. Numa the king seated in this place. Nero could watch the fire of Rome from the today site-seeing spot! A tiny Palatine museum give you the perfect picture trough the elapsed ages what was Palatine and what it wasn’t. On-line Express ticket is a nice solution to enter (nevertheless express queue will be shorter than no-express ticket line) but it’s more expensive version is useless. The more expensive ticket give you the access to almost all significant site-museums but in a queue! This is in every spot on the hill; you go to Palatine museum and wait there, then you go to House of Julia and wait, then again.. Essentially, you will spend all your time in lines all around the hill. Very inconvenient, disappointing and frustrating. I can only advise to buy the cheapest ticket on-line just to enter and then just to walk around. This will certainly save you time and nerves. After all the site museums are less likely important to visit if you know everything already. So, better is to prepare yourself to the visit, to read some wikipedia at least..