Right here.
I grew up with the original (G1) MLP, so I can see some of the nods to the original (the most recent being Tirek's appearance in "Twilight's Kingdom").
Lately, I can't really pick a "favorite" - every character contributes something important.
If pressed, I'd say:
Discord (long-time TREK fan );
Derpy (like many other fans, I see her as overcoming a lot of difficulties, which I can relate to. My friend got me a Funko vinyl figure of her for Christmas);
Twilight (she's really growing into her princess role well, without being a Mary Sue);
Luna (her character development has been done really well);
Rainbow Dash (I like that she's encouraging of others without putting down what they can do "now");
Fluttershy (her character development mirrors how I've changed socially over time);
and, Pinkie Pie (just because ).
_________________
The existence of the leader who is wise
is barely known to those he leads.
He acts without unnecessary speech,
so that the people say,
'It happened of its own accord.' -Tao Te Ching, Verse 17