I like Palma a lot. Reminds me a bit of Barcelona, but on a more modest scale.
You probably know about this if you have read anything at all about Mallorca, but you can take the train from Palma to Sóller which is a good excursion. If you intend to make the trip to Sóller, take a look at these food and wine comments based on my stay in Sóller this year.