Wonderful news! A shiny Totodile. That is funny, I go by Sam- as in Samantha. Well he will be cute when you see him in Poke Refresh before you begin your training. I think Totodile's cheerfulness makes him the most fun of the first stage Johto starters, though Chikorita's line is the loveliest to look at overall. In Oras post game when I got my Johto starter I went with Totodile, gave it an everstone to keep it adorable and then it exchanged stone for scarf and embarked on a contest career. It gets some really good tough, cool and cute contest movesets.
On Sabrina I'm happy with her appearance basically in gen 1, I like that she looks brooding and stern, but what I don't like is that she carries a whip in the original Red Blue games. So I would definitely pick her more recent sprites. The 1st season episodes with her are some of my all time favs though. I love how they paid homage to the Twilight Zone with her dollhouse. As a doll collector myself it makes Sabrina that much more interesting to me.
Now Ghetsis, he is something. I think he is actually the best final boss fight of the main series games, even though I can't count him as a champion. I wish they hadn't nerfed him in BW2, that was sad for me as his fan.
For some reason I always do very well against Marshall. I was proud of my Serperior in my last run of White 2 for sweeping Marshall's whole team by himself. The fighting type that is hardest for me to counter is Machamp, which thankfully Matshall only has in rematch on challenge more. Grimsley is the e4 member who tends to delay more often because his attacks are so sneaky!