A good television show can be a uniquely rewarding experience. Whether it's the kind of series that warrants a weekly calendar appointment or one that's built to be binged, when we spend so much time with a set of solid screen characters it often results in real emotional investment which can pay off in very meaningful ways. We experience the highs right alongside our favorites. On the other hand, becoming so attached to these fictional friends can also be pretty punishing when their fates are not so fortunate.

Over the years, there have been a lot of TV character deaths that shook us to the core. Some were completely unexpected and rattled us with that shock factor, while others were fairly foreseeable but still hammered on our hearts. In every case, the pain we experienced while watching was real, which is a testament to the show's creatives and the actors portraying these people.

To celebrate those series that made us care the most about the characters they killed off, we rounded up our picks for TV's most devastating deaths. From the doctors and patients who died in hospital dramas like ER and Grey's Anatomy to the characters who stood out among the massive body counts in Game of Thrones and The Walking Dead to the more light-hearted series that stunned us with a serious loss like How I Met Your Mother, click through the gallery below to join us in mourning some small screen favorites whose demises we still can't get over.

PHOTOS: TV's Most Heartbreaking Deaths Ever

Dominic Monaghan, <em>Lost</em>Dominic Monaghan, Lost