I have to say, I cannot get over how awesome Castle is. Not only is the show well-written with great actors all around, but Nathan Fillion keeps making Firefly references! Those of you that saw last week's episode, Fool Me Once, did you catch the 'shout out' 6 minutes in? If you're on Twitter, I would recommend following both Nathan Fillion (@NathanFillion) and Castle (@WriteRCastle) as they both tweet about the show. Castle has a Facebook account, too, so add him as a friend if you prefer that to Twitter (don't worry - they don't ruin anything before the show airs).
Although Castle is probably my favorite show airing at the moment, there are quite a four others that have been holding my interest:
The Big Bang Theory: With a premise of 4 nerds and 1 hot girl, how could it not be amusing? I love all of the characters' quirks, and appreciate the nerd humor I understand (although they're good at keeping it from going over my head but, as I hear, still very accurate). Apparently Wil Wheaton is on this next episode, so there should be some fun Star Trek references!
NCIS: Honestly, it's the chemistry of the characters that keep me hooked on this show. I mean, I liked it when Kate was on it too, but I didn't need to watch every episode the same way. Ziva brings a lot to the group, and I like the way the actors portray their characters (especially Abby) now that they've had a few years to settle into their roles. PS - Gibbs is awesome.
Glee: Okay, this one is totally a guilty pleasure. The plot is a little too overly dramatic for me, but the songs are just so fun! They're what keep me hooked. My favorites so far were "Don't Stop Believing" in the pilot and the Bon Jovi/Usher Mashup in Vitamin D.
Survivor: As fun as this show is, I never got into it until my brother suggested Fantasy Survivor. This has turned Survivor into a game we can play together even though we don't live near each other. We each pick an MVP at the beginning of the show (go Brett!), and then each week we make picks for who's going to help win reward/immunity challenges, get voted off, be safe and then one mystery question that changes each week (i.e. whose vote will be shown on camera or who will be shown holding the immunity idol).
On that note, I haven't watched NCIS yet this week and really need to go watch it...so I will.