Tivoli

I suggest that you use the search box (top center, desktop version) because the subject has been very helpfully covered in the past. It includes references to the RonInRome site, which is great, but the past threads will persuade you how easy it is do do this independently. Note that there are TWO major sights in Tivoli, not next door to each other.

Edit: I don't retract my observations, but I do agree with th spirit of Chani's post below. There are annoyances involved with the busses, and we did some long, hot walking. We have used package daytours in other cities to hit multiple out of town sites in one day.

If u are doing only a day trip from Rome, then i would take a guided tour from Rome.
However if u decide to stay in Tivoli then a self guided works fine. We stayed 3 nites and saw all on our own. We used public buses and taxi when necessary.
U will want dry weather to see Hadrians masterpiece, which is iffy in Oct.

If you overnight in Tivoli, it's easy to see both sights in one trip. Hadrian's Villa is not that convenient via bus to the Villa d'Este. The city of Tivoli has a few other things of interest as well.

Just visited the 2 main villas 3 weeks ago. We stayed 10 minutes from Tivoli and as someone mentionned, easy to visit them both the same day.
2 great visits, 2 very different villas as Villa d'este is dating from the 1500's while Adriana is from 118 AD.
I had a small preference for Adriana as I'm always impressed by 2000 year old buildings.
But it was a great day and well worth both visits.

We did a day trip from Rome on our own that included both Tivoli/Villa d'Este and Hadrian's Villa. We used public bus for the entire day, following RS suggestions. It was easy and we had no problems. I like gardens a lot but touring the Villa d'Este and the grounds didn't take too long, even though I walked around in circles to be sure I'd spent enough time. After the Villa d'Este we walked around Tivoli for a short bit, then walked to the bus stop for Hadrian's Villa. We ate a nice lunch at the restaurant opposite the entrance before visiting. These grounds are huge and one could walk for hours.The bus back onto Rome was packed...it was 5 pm or so...but no difficulties and a rewarding day. Safe travels.

I took a guided tour run by Enjoy Rome, but I booked it thru Viator because their price was cheaper. The tour was efficient, the guide was good. I wanted to see both Hadrian's Villa and Villa d'Este and public transportation was reported to be a little tricky - finding bus stops, coordinating the schedule. I felt I got a better understanding and appreciation of Villa d'Este after seeing Hadrian's Villa, especially with the guide's explanations. There was time between the two sights to either have lunch in Tivoli or explore the town. Most of us ate at the the restaurant recommended by the guide and all were pleased with the food, the service and the price. I would have liked more time at Villa d'Este and to see Tivoli but I was getting tired, so I was fine with getting on the tour bus and returning to Rome. I'm sure if I'd wanted to, I could have opted to stay and take public transport back to Rome for a few euros.

Tim - Sadly, the RoninRome site is no longer available. I have searched for this information as well and wasn't able to figure a definite answer.

Mading - We will be there about the same time and will be staying in the same area.