I would really like to see a volcano in Italy. The world-famous Vesuvius would be a good choice, but wikitravel describes it as "congested by pensioners", which is a no-go for me. There is the big Etna (>3000m) on the south, but I am not sure whether you can ascent it without a guide, which would be an another no-go.
What are another beautiful, big, hikable, off the beaten track volcanoes in Italy, that are worth visiting? By beautiful I mean a lot of wild nature and that the rocks should expose their volcanic origin. It should feel like a volcano, not like just one another mountain, shouldn't it?