I'll break down my viewing habits on a day-by-day basis for when I watch these shows...
Sunday--Once Upon A Time: I've mentioned over in VCR Alerts that this season's villain (a Snow Queen antagonist, building off the inclusion of characters from "Frozen") is played by Elizabeth Mitchell, in a sparkly cleavage-baring dress. In addition to the eye candy, the Snow Queen is proving to be one of the better antagonists, matching series baddie Rumpelstiltskin in ambitious/deranged plotting. It's come across rathe well, and hopefully she (and the other inclusions from Frozen) will stick around for the long haul.
Monday--Gotham: This is basically a crime drama/procedural with a heavy dose of mafia manipulations, all in the setting that will eventually give rise to Batman and his rogue's gallery. The actors for Gordon and Bullock have settled in to a good rapport, and the guy playing Penguin is killing it (as the character does, both literally and figuratively). Also, Jada Pinkett Smith looks darn good in outfits that look close to the sort of outlandish fare found in comics (even though her character is a brand-new one), and the guy playing Alfred is the son of Doctor Who's Third Doctor, and doing a great job too. I don't think a fondness for Batman is necessary to enjoy the show, but obviously it helps.
Sleepy Hollow: Continues with its outlandish original premise, and it's fantastic to watch. There's great chemistry between the two lead characters, and they both have great dialogue that helps to lighten the otherwise "serious"/dark tone the show has (fighting against the forces of the Biblical apocalypse). Also, the actress playing Abbie is simply gorgeous.
Tuesday--The Flash: Of all the shows set in comics/superhero universes, this one is the most straightforwardly superhero-y, with Barry Allen gaining his superspeed in the first episode and coping with the sudden existence of other superhumans (or ordinary humans with super-tech). In true Flash fashion, it's much more optimistic/upbeat than the current trend of "dark/angst" sensibilities, which I find refreshingly enjoyable. There's a couple of crossover moments with "Arrow" which airs on the same network, but I don't watch that series and didn't really have any problem (I expect there'll be more cropping up over time, depending on how much cross-promotion they want). In the meantime, they're doing a great job of building their own part of the DC world, with nifty little tidbits/Easter Eggs for coming potential material.
Agents of SHIELD: I think they hamstrung themselves a bit in the first season, as there was a major (and awesome) shift with the big plot-twist that came in play from the Captain America: Winter Soldier movie. All the episodes leading up to that (which was the majority of the season) were kinda spinning wheels, while the ones after (the last few of the season) were where the show finally kicked into gear. Now that that's done, SHIELD's gotten significantly better, though there are some concerns that Avengers 2 comes out near its season's end, so it's possible they may stretch or strain the show in order to make a bigger impact thru the movie (but the the series' detriment). At any rate, I still find it enjoyable and it's great to watch Ming-Na Wen's Melinda May in action. She's 50, but looks fantastic, as in the recent episode where she fought an enemy agent in nothing but a slip. And they've also recently added Adrienne Palicki (of the aborted mess of a Wonder Woman pilot), who's also quite attractive and kicks butt handily too.
Wednesday & Thursday are out for me at the moment, at least until Parks & Rec comes back (I believe it'll be its final season).
Friday--Grimm: The recent additions of runaway Grimm Teresa and creepy-ally Hexenbiest Elizabeth have both improved the prospects for the coming season (in my estimation). Teresa's a good character and may end up being a catalyst for Sgt. Wu to join the team, while Elizabeth is already more interesting than Adalind (who's yet again stuck in a storyline off in Europe). The writers do have a tendency to drag out these personal plotlines for little discernable purpose, but they have a few more than normal this time around so I'm willing to give them leeway as long as they do come together and get resolved in a good/memorable/entertaining way.
Saturday--Doctor Who: Okay, mentioning it is a bit of a cheat since the finale was last week, but they really did have a phenomenal season this year. The "soldier" (and "officer") theme, Missy's appearance and plotting with an afterlife were all much more relevant and tied together better than just about any previous season since the show returned. Capaldi and Coleman both did a great job with their respective characters (I thought) this season, but it seems we won't have them as a duo anymore, which is almost a shame but ultimately okay as I'm definitely interested to see who might get paired off with the more "blunt" sensibility of the Twelfth Doctor. Also, a Christmas special with an actual Santa Claus sounds just bonkers enough to be fun.
Legend of Korra: I catch this up on Saturday evening (rather than whenever it "airs"). I managed to give the first Avatar series a shot some time back, found it to be really quite awesome, and have thus been following LoK more recently. It's in its final season and going very well, with great moments for all the main characters as the end comes.
TMNT: I'm also watching this on Saturday rather than its regular airdate, and they've been a bit annoying (as in previous seasons) with spreading out the season's schedule. However, by the same token it's almost kinda brilliant since the show isn't away for more than a month or so at a time, even in between seasons, which makes it feel more strongly continuous even with the big cliffhangers. I also have to give them respect for managing to incorporate elements from both the previous animated series and the original live-action movie in creating a vision for the show that both feels familiar while also being completely distinct. I mean, I didn't see the twist with Irma coming AT ALL, and it was ridiculously great. I'm a little concerned that the current season has seemingly stalled with the team in upstate NY (borrowed from the first movie), but that may just be my anxiety to see what-all else has been happening in NYC, b/c there were multiple cliffhangers going on and I'm eager to see the resolution of the others.
I think that pretty well covers all the major series I'm invested in currently. I do catch some other shows from time to time, but not with any serious commitment and can't recall them at the moment.