Back in the day when everything started for me when it comes to getting into the series through HG, I was mad with love for Absol. Then I got a shiny Charizard ready for battle through a trade in HG and fell in love with its dark color. In X/Y, it was probably Medicham and some others like Xerneas and Yveltal. Now a days my favorite pokemon is without a doubt Mawile. I am glad he/she made the cut in Sw/Sh. Sad to see many of my favorites didn't make it.
Typhlosion is number one, but it's tied with Quilava and Cyndaquil, I love them all equally. Scolipede is number 2 and Pidgeot number 3. Then out of these I also really like Slowking, Kabutops and Krookodile the most.