I've always liked halfcrowns, due to the depictions of the coat of arms that most of them bear. While my personal favourite is always going to be the 1887 Jubilee halfcrown, the Edwardian halfcrown is nice too. The colonial ones of the later 20th century match nicely as well.
Not everyone liked the design at the time, however. I recall finding an Australian newspaper editorial article from the time of Edward VII (Adelaide advertiser, 18 August 1909 - Australia had not yet started issuing its own coins and was using British coinage at the time) denouncing the halfcrown as "ungainly" and "this inartistic and inconvenient disc". Australia was one of the few dominions not to issue its own halfcrowns, apparently because of that whole "inconvenient" thing.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis