Rome to Catania - which airline?

My experience with Alitalia has been good on domestic flights. Be sure to check baggage allowances, since Alitalia's seems to be a better deal. I was surprised that the seats in regular coach were so comfortable.

I have flown Vueling as well, and it was fine.

Given how short the flight would be (it's not even 2 hours), my only criteria would be schedule and total price. Why would you be inclined to avoid Ryan Air? All three of your airlines are considered comparable (same class) according to Skytrax - all are 3-star airlines. Just read any differences in rules, baggage, etc. when comparing total price.
http://www.airlinequality.com/ratings/3-star-airline-ratings/

I also agree with Zoe. In October I took Alitalia flights RT from Rome to Càgliari and from Verona to Rome. Flights were comfortable, on time, handled my checked bag efficiently and even offered free snacks and beverages on the flights. I was also able to change my flight to Càgliari to an earlier flight at no extra charge when my flight from the States arrived a little early. No baggage fees, no reservation change fee, free Coke!

We've flown Vueling the other way - Catania to Rome - and it was fine. If you do choose a budget airline, be sure to book as soon as possible, because prices often go sky high (so to speak) at the flight date approaches, Also, be prepared to pay extra for luggage or choosing your seat. (Although, we just paid extra to choose seats on British Air business class. Grrrrr!)

I've made a reservation on Ryan Air in reversal from what you are needing, mine is Catania to Rome next March 2017. Not happy with them because after booking my ticket they changed my departure time. I checked and found out several months later that my departure time had been changed and they never notified me. Now I leave 30 minutes later to Rome. As Ryan Air arrives and I would think therefore also departs out on the tarmac (bused from your gate or to gate) this eats up time. So I will probably have to dump my Ryan Air ticket and book an earlier flight on Ilitalia from Catania to Rome to make my flight back to the US at terminal 5. I could not recommend Ryan Air if they go changing your flight times and don't even notify you. They are now on my "not happy with" list.

I would never book a separate ticket to connect to a longer (especially a long-haul) flight. The chances of something going wrong are just too many - delays, luggage collection . . .

When I went to Sicily, I flew Alitalia for just that reason, open-jaw into Palermo (connecting in Rome) and then home from Rome. After my time in Sicily I flew on a budget airline from Catania to the mainland for a few days. I knew that there were at least 2-3 more Alitalia flights from Rome to Palermo that day and Alitalia would have to get me and my luggage there, one way or another. If there was a problem from Catania, it would not have impacted my flight home, just my Italian itinerary.

I did the reverse trip too. Catania to Rome. I was on Alitalia and friends on the Ryanair flight that left about the same time. Early morning flights as we all had connections in Rome on separate tickets. On this particular day my flight used the bus and tarmac boarding at both airports. My friends boarded their flight from the jetway.

They had the business fare not class but fare. It includes reserved seats, exit row I think, and checked bags. They had no issues with the airline but make sure you know and understand all the rules.

I had no issues with Alitalia. As has been reported here if you book on their website, then go to the upper left hand corner and pick international as the country. Your flight will be priced in euros but will be lower. I think I saved about 40% to 50%, but I had a checked bag.