I am a huge fan of having something your guests have never had on your bar - it is a conversation starter, and will have people giving something new a try. I pick up little bits and bobs when I travel, and keep an eye out for unusual things in bars here (and then go to the liquor store to get a bottle if it is something I like). What this often means is that my bar contains as many weird and wonderful items as standard, and it makes for some good cocktails! My last 5 purchases were (and of course this will depend on what is 'normal' where you live, some stuff is utterly normal in the UK, but not in Toronto!): Creme Yvette, Luxardo Maraschino Liqueur, Chase Marmalade vodka, Liquor 43, and an Elderflower liqueur from a small batch producer.