I've been looking for inspiration for a boxset since finishing Sopranos recently. I didn't think anything would top The Wire but The Sopranos maybe just pipped it.
Had all of the Lost series as well but as everyone knows, that went out with a whimper so I sold my collection.
I enjoy being able to watch the next episode whenever I feel like it so I tend to wait for shows to finish before sourcing the DVD boxset. I couldn't wait a whole week between episodes, or months between seasons.
From reading the above, Breaking Bad sounds good. It's always been the intention to watch the likes of Oz, 24, Prison Break as well. And it's even better knowing that Hollywood just keeps churning out more great TV, like Boardwalk Empire and Treme as they will be sourced some day too.