I am with Billy and roast my own. I have got around 30-40 kilos of green beans. Ethiopian Harrar and Yirgacheffe are a couple of my favs, either macchiato or piccolo late. But I do like many south american varietys, and Indian Monsoon Malabar, Papua New Guinea Waghi.
Taste is a preference thing, some like coffee weak and sweet, and they will call this 'good coffee'. Nespresso is convenient, simple and consistent. I would say consistently poor, but that is my taste. Coffee like any food goes stale, it is at its best for up to about 4-5 weeks after roasting. Beyond that it is stale. Some beans taste great a few days after roasting (generally South Americans) others taste better left to rest a couple of weeks. Coffee should be ground immediatley before brewing. Coffee that is bought pre-ground is not going to be much good. Anyways I am getting a bit carried away about coffee I just really like the stuff.