I still love the dynamic between Castle and Beckett, of course -- snarky banter and unresolved sexual tension are weaknesses of mine. But watching season two also made me realize how wonderful the supporting characters are. Ryan and Esposito may be my favorite supporting duo ever. They're so funny together and every scene is better when they're in it. I enjoyed how the writers use the fact that Ryan is totally whipped by his girlfriend as an ongoing bit of comic relief; it's not only funny, but it acts as continuity to weave all the episodes together. I especially liked the episode that focused on the supposed death of Esposito's former partner ("Den of Thieves"). Jon Huertas did an amazing job in that ep, and I hope the writers continue to do the occasional episode that focuses more on the supporting characters.
The two-parter with the serial killer was awesome ("Tick, Tick, Tick" and "Boom"). I was shocked when Beckett's apartment went up in flames at the end of part one. Of course, since I was watching the series straight through I immediately went to part two to find out how she survived, but I can only imagine how stressful it would have been to have to wait an entire week to find out what happened. Plus, it's always nice to see Dana Delaney in a guest starring role. I've been a fan of her work since the short-lived TV series Kidnapped (if you've never seen it, check it out...it's only 13 episodes)
I'm trying to figure out what my favorite episode of the season was, and it's rather difficult for me to decide. I think 1.7, "Home is Where the Heart Stops," is my favorite from season one...I just liked the whole jewel heist thing. "Vampire Weekend" from season two was really fun, and I also enjoyed the "The Third Man" (A man squats in people's apartments while they're on vacation and they never know? Pretty creative!).
I'm excited for season three! Hopefully my schedule will allow time for me to actually watch the episodes as they air. I am dying to know how Castle's reconnection with his ex-wife is going to affect his and Beckett's working relationship. I already went on a mini spoiler expedition last night after I finished season two (Ugh, I'm such a spoiler whore!). :-)