For me, there is nothing more inspiring than just looking at a ton of stuff. Although it may not be the most professional way to go about designing, it sure gives me ideas. These are some of my favorite inspiration posters; clearly I focus more on typography than actual illustration, which I think is pretty telling of my personal style.
One of my favorite bands! I love the flower child theme they've got going on. It's a much needed and drastic change from other band posters circulating the lampposts.
Pink and red are two of my favorite colors (especially together), and I think this poster does it in a nice, subtle way. The designer lets the text scream at you rather than using just the color for impact.
Chartreuse! Ah! I love it! And I know some people hate filled bowls, but I think it can make an impact when needed. It can be particularly effective and more relevant when used for events and publications that cater to designers; they can appreciate it rather than wonder what happened to the "Os."