Some shows are just classics. And even years from now, they will forever remain a classic. This is one of them. This show was blessed with good writing, good directing, good producing and an amazing cast. When you have all of that, it will forever be a classic. It doesn't matter how many times you've watched Castle, you are still amused, entertained and smitten. If you love romance this is for you. Stana and Nathan had hands-down one of TV's best on screen chemistry. If you love mystery and action, this is also for you; you'll be surprised at some of the story lines and plot twists. If you love comedy, saddle up, you will spit out your water. This has everything. I heard there was some tension about one character shining too much but a diamond has to shine, you can cover it up, but it will still shine. And I believed overall it really worked well for the show.
Critics say there were some issues with the baseline plot of the last two seasons; unresolved mysteries that should have been examined further and while I agree- the show still somehow managed to capture the love, mystery and action of the character's lives so I try to ignore wanting everything answered.
All in all, this show was so well done and will forever be One of the Classics on TV. Good job guys.