Really interesting and a good day out whether or not you are particularly interested in art. The variety of work (paintings, sculptures, jewellery, etc) is fantastic. We have left a book that is full of illustrations and background in the Villa. See also this website that has 25 of his most famous paintings.
Parking (early July) was relatively easy (10 Euros) and entry was 12 Euros each (9 Euros concessions). One word of warning ... although Figueres and the Dali Museum are well signposted as you head South on the motorway ... once in Figueres it is a bit more tricky and we relied on the Sat Nav !
Figueres itself looks a nice little place itself. There are many catalan style restaurants that surround the museum so light refreshments / lunch afterwards is a good option.
We then drove 20 minutes to Roses, a small beach resort town ... just to have a look but it looks nice and maybe worth a separate day trip in the future.