Sardinia for first timers 10 day vacation recommendations

Honestly, the first suggestion I would make is to give Sardinia more time - as much as you can. Here's why:

Sardinia is not well-known to most North Americans (note: this is a feature, not a bug). But it's definitely popular with Europeans (this means parts of Sardinia get busy/crowded in peak season), so one is wise to go outside of June and especially July and August, when it's most popular/crowded. Well, you're going in May, so good choice there.

Sardinia is big - a lot bigger than most first-time visitors expect. Roads tend to be two-lane and twisty (coastal roads hug cliffs most of the time - it's spectacular, but slow-going). So it takes time to get around. All that means that it's hard to "do" all of Sardinia (and do it justice) as a quickie side-trip from your larger European vacation. I think this is a mistake many (most?) people here make when initially planning a trip there. It's like, would you recommend going to see Sicily (or France...) for a long weekend, as a side-trip from your larger trip to Italy? If that's all the time you can give it, maybe, but boy howdy it'll be better if you slow down.

Sardinia has great, spectacular stuff to see and do, but those things are inconveniently scattered all around this large island. With 7-8 days, you can maybe swing through 25%-50% of the island, but you'll be moving fast and still will have to skip most of it. We spent ~18 full days there, not including arrival/departure days (more than twice the time you're looking at), we moved very fast, and still had to skip a lot of places that looked worthwhile. That said, that was one of the best trips we have ever done. My wife, who always tell me we need to go to new places rather than repeating any, wants to go back to Sardinia.

All that said, if all you can manage is 7-8 full days, you will have to make difficult choices. There's plenty of great stuff along all the coasts - the north, the west, the south and the east, plus the interior. You could easily spend 7-8 full days (or longer) in any of them and still not see it all.

I think the question "which part of Sardinia to see?" is the same as asking "which part of France or Italy to see?" Think of Sardinia not as a little island you can knock out in a week or a long weekend, rather, it's pretty much a separate country (that just happens to be part of Italy these days) with a rich and complicated history, multiple distinct cultures that have been influenced by many others, with many interesting cities, beaches, scenery and natural beauty. I think it's worth a dedicated trip all its own, rather than being an added-on side-trip to a trip to Italy.

Our favorite bits that we enjoyed most?

• The northwest (La Maddalena archipelago)
• The north coast (Santa Teresa Gallura, Castelsardo, Stintino)
• The west coast (Alghero, Bosa, Oristano, Sinis Peninsula, Tharros)
• The southwest coast (between Oristano and Sant'Antioca)
• Carloforte
• Cagliari
• The southeast coast from Costa Rei to Santa Maria Navarrese
• The Parco Nazionale del Golfo do Oresei
• The east coast, from Santa Maria Navarrese to Cala Gonone to Sanya Lucia

There's a lot to see. Great food. Few crowds if you time it right (sshhhhhhh...).

Hope that helps a bit.

Sardinia is lovely. I agree with what David says above. We did a one week trip a few years ago and just stayed in two places- Alghero and Santa Teresa di Gallura. Alghero is one of the best old towns in Europe and has a lot of Catalan influence, which makes it quite interesting considering it's now part of Italy. Great beaches as well. There's also an airport and you can probably fly there directly from Rome (the three big airports are Cagliari in the south, Alghero in the west, and Olbia in the north- all have direct seasonal flights from London so I'm sure they do from major Italian cities as well). Santa Teresa di Gallura is well located if you want to spend time at the beach and/or visit the Maddalena Islands by boat, which are some of the best beaches in Europe. You can even take a ferry across to Corsica for the day if that is of interest. I'm less familiar with the rest of the island but for a first time, one-week visit that worked well for us. By the way, the public transport isn't great so I would rent a car if you plan to move around. Good luck with your planning.

I agree more time is always better, but even with two weeks you would have to make hard decisions, so the most important thing is why you want to go. Are you interested in beaches, hiking, archaeology? You need to tailor your trip to your interests, so just throwing out random suggestions is not as helpful as sussing out what kinds of experiences you are after.
I flew to Olbia via Germany on Lufthansa, and I believe Swiss had some good flights as well. I think you can bypass Rome without that much more expense. And time is money!
In late May, the seas are just beginning to warm, but I found it a great time to be there.
Car is vital unless you just want a city break and maybe one beach excursion.