what is your favorite season and why???

For me it's a dead heat between seasons 3 & 4. It was already clear about Castle's feelings for Beckett; these seasons were all about Beckett's feelings.

Season 3 had Beckett gradually evolving her feelings for Castle from affection to love. Best episodes, chronologically: A Deadly Affair, Last Call, Nikki Heat, Knockdown, Setup, Countdown, To Love & Die in L.A.

Season 4 showed Beckett coming to terms with, and realization of, her love for Castle. Best episodes, chronologically: Rise, Eye of the Beholder, Demons, Cops and Robbers, Kill Shot, Cuffed, Pandora, Linchpin, 47 Seconds, The Limey, Undead Again, Always.

I liked the first few seasons because Castle still had a brain.

_________

No, David. No one is happy in a poodle skirt and a sweater set.

Season four stands out for me.

So many excellent, memorable eps.

The fist.

The one where Richard and Martha are held hostage in a bank.

Any ep where Kevin is centric. So the one with the frantic CPR sequence near the close of the ep.

The superhero ep.

The bomb/rally ep.

I really liked so many episodes for different reasons, and Castle and his family, and the supporting characters, but overall probably Season 5. That's the one I liked most, but I don't think it was best.

I think the core reason of Beckett's drive, all the lead-up climaxed in season 3, and that was all the most touching for me. Montgomery's confession and redemption. Beckett's learning it had far deeper connections. The subsequent fall out went on too long imo, and although I might complain initially that the "bad guy politician" just wasn't obviously "bad" enough to really cheer against, he was EXACTLY the type of scum all through US elected officials.

I did like season 4 a lot too, but the back & forth of Castle and Beckett's relationship got on my nerves. I liked them getting together, I could understand some of Beckett's issues, but she was easily getting with other men all along, so I never understood her continuing issues with Castle. He was devoted.

On consistency, I think season 2 had the most consistently above average episodes, well-rounded and engaging. No issues about Beckett's insecurities. Again, I got them, but they were unevenly placed, unique to her character sure, but just annoying for me. It all became completely ludicrous into season 7 and 8, but of course, writers were different. Combined with the dummification of Castle, and the issues behind the scene?

"I understand English very well...." Magua, The Last of the Mohicans

One is the best. Two is good as well. It kind of went slowly downhill after that.

i tend to prefer the earlier seasons overall.
season 5 became kind of shark-jumpy. . ...