Friendship is Magic part1 AKA "Mare in the Moon": Mane 6
Looking back, I've realized something: In Part 1, We, through Twilight's 1st impressions, see the main negative side of the Mane 5: Applejack's too eager to introduce her whole family; Rainbow Dash is lazing around, despite being brillant enough to clear the skies in 10 seconds flat; Rarity is obsessed with Canterlot "Let's get out of here before she dyes my coat a new color"; Fluttershy is too shy to speak except to Spike; CONFOUND THAT PINKIE PIE! SHE DRIVES ME TO DRINK!. In short: Twilight's 1st impression was "All the ponies in this town are CRAZY!" This is Pre-character development for her.
Friendship is Magic part2 AKA "Elements of Harmony": Mane 6
At first, Twilight felt she had to find the Elements of Harmony on her own as the Mane 6 are about to enter the Everfree Forest. But as they journey on, Twilight (as well as us) see the strongest Element of each of these "crazy" ponies: Over-eager Applejack is Honest; Quiet Fluttershy is Kind; Annoying Pinkie Pie Laughs away the illusions; Obsessed Rarity is Generous; Brilliant, but Lazy Rainbow Dash is Loyal! By the end, Twilight's made friends for the first time in a very long while that she didn't want to leave them. This is post-character development for her. And there'll be more ways for her to improve as the series goes on.
Ticket Master: Mane 6
Mostly Centered on Twilight, but we first see the hopes and dreams of the Mane 5.
Applebuck Season: Applejack and Twilight Sparkle
While A.J. stubbornly tries to buck all the apples on her own and go to help out her friends, Twilight tries to act like her voice of reason to get her to accept help.
Griffon the Brush Off: Rainbow Dash and Pinkie Pie
Dash and Pie start hanging out over their mutual love of pranking. Pinkie tries to improve the attitude of a grumpy griffon named Gilda, an old friend of Rainbow Dash, with a party. In the end, Rainbow loyally sticks by her pony friends when Gilda's nasty side is revealed.
Boast Busters: Twilight Sparkle and Trixie
I chose to include Trixie as she contrasts with Twilight well. Her bragging stage magic was outdone by Twilight's real magical talent that protect Ponyville from incoming danger. I'll talk about the opposite of that later when we get to Season 3.
While this episode features the Mane 6 traveling up the mountains to awake a sleeping dragon, this episode focuses on Fluttershy surviving her fears along the way. She finally does stand up when her friends were hurt. On a side note this episode is great for comparing Dash's evolving attitude towards Fluttershy; Dash may greatly complain about Shy being the Load here, but as we'd see in later episodes, her attitude towards Shy gets better as character development kicks in.
Look Before You Sleep: Applejack and Rarity
I've heard that in Applebuck Season, there was going to be a scene where Applejack would help Rarity with something, but time constraints forced the idea to be dropped. This episode makes up for it as it has two contrasting personalities at odd with each other. In the end, Obsessed-with-the-Small-Stuff Rarity had to deal with the huge fallen tree first, using her magic to transform the majority of the tree into smaller manageable plants; Over-doing Applejack had to gently and carefully drop the tree's remains out, rather than aggressively buck it out. Even to this day, I consider this episode to be the episode with the most focus on the two of them.
Bridal Gossip: Mane 6
It's simply how each of the Mane 6 were affected by the Poison Joke: Rainbow Crash's upside down wings, Harity's overblown mane and fur, Appletini's small size, Spitty Pie's swollen tongue, Flutterguy's deep voice, and Twilight Flopple's limp horn. Need I explain more why the whole Mane 6's got the spot?
Swarm of the Century: Mane 6
As much as you would believe Pinkie and/or Twilight should have this spot, everypony acts and reacts to the Parasprites in different ways in this episode. Everypony of the Mane 6 gets a chance to shine here for better or worse. Even those whose actions cause the problem in the first place.
Winter Wrap Up: Twilight Sparkle
Simple. Twilight trying to find a way to help the Winter Wrap-up while respecting the Ponyville tradition to not rely on Unicorn Magic to change the seasons like the Unicorn citizens of Canterlot are said to do.
Call of the Cutie: Apple Bloom
While we have seen Apple Bloom both in Mare in the Moon and Bridle Gossip, here is where she and the other CMC make their official debut. The funny thing is when Nightmare Moon first returned in Mare in the Moon, all three of the CMC hid under the same table, but never got properly introduced until now. A fine example of Forgotten First Meeting
Fall Weather Friends: Applejack and Rainbow Dash
The two Mane Ponies voiced by Ashleigh Ball compete to see who's the better athlete. Simple as that. Plus, we get to see Pinkie Pie and Spike work off each other as co-commentators.
Suited for Success: Rarity
Just simply Rarity having her generosity being taken advantage of by the Mane 5 and the Mane 5 realizing they've been too demanding.
Feeling Pinkie Keen: Twilight Sparkle and Pinkie Pie
To this day, this episode is the one to have the spotlight on Twilight Sparkle and Pinkie Pie together the most. Twilight spends whole episode trying to make sense of the Pinkie Sense.
Sonic Rainboom: Rainbow Dash and Rarity
While Rainbow Dash is the main character to compete in the Young Flyers competition in Cloudsdale, Rarity is the one to learn the lesson when she nearly fell to her death: "I should keep my hooves on the ground and be there for my friends."
Stare Master: Fluttershy and CMC
Simply Fluttershy foal-sitting the CMC, and realizing how she bit off more than she can chew. The CMC also speculate what they might get their Cutie Marks for.
The Show Stoppers: CMC
Simply the CMC trying different things to see if their Cutie Marks appear.
A Dog and Pony Show: Rarity and Spike
It starts with Rarity and Spike together until her capture at the end of Act 1. Throughout most of Act 2, we see Spike and the Mane 5 worrying about Rarity's predicament. Until Spike and the others catch up, we see Rarity throughout Act 3 actually managing to pull a fast one over the Diamond Dogs. These kinds of episodes are nice to watch sticking to either one or the other character's POV. Try it!
Green Isn't Your Color: Fluttershy and Rarity
Rarity gets an audience with Photo Finish, but unfortunately Fluttershy gets the modeling job. Rarity is jealous, but wants to be supportive of her friend; Fluttershy hates the modeling job, but keeps going because of Rarity's insistence. Also this episode has a subplot of Pinkie making sure Twilight keeps her Pinkie Promise, despite the fact it would have resolve the plot faster if she was allowed to speak.
Over a Barrel: Mane 6
Honestly, this is more between the Native Buffalo Tribe and the Pony Settlers of Appleosa than our Mane 6, but we still watch all this from their POV.
A Bird in the Hoof: Fluttershy and Twilight Sparkle
While it's mostly focused on Fluttershy tending to Celestia's sick bird without permission, Twilight is also in the spotlight for how nervous she gets during this episode. In Act 1, Twilight is nervous about her friends making a good first impression on the Princess. Later on, when she finds out that Fluttershy has taken Celestia's bird, she fears she might banish Fluttershy from Equestria or throw her in a dungeon or banish her and throw her in a dungeon in the place that she banishes her to. Near the end, when it seems the bird has died, Twilight tries to take the blame for Fluttershy's sake. So yeah, I argue that this is the first (but definitely not the last) episode to focus on our two introverts.
Cutie Mark Chronicles: Mane 6 and CMC
Simply our Mane 6 telling their backstories to the CMC.
Owl's Well That Ends Well: Spike and Twilight Sparkle
While mostly a Spike episode, this episode also shows how much being Twilight's number one assistant means to him.
Party of One: Pinkie Pie
This one is quite obviously focused on Pinkie Pie and her worries about being ignored by her friends. Plus we get another episode with a scene of Pinkie and Spike working off each other.
The Best Night Ever: Mane 6
Each of the Mane 6 get screen time of them pursuing their expectations at the Grand Galloping Gala. But as it turns out, their hopes, wishes, and dreams didn't go the way they thought. In the end, their efforts to make this the best night ever led to a very humorous conclusion.