Eh I'm between a couple. I've loved Gengar since I first saw him and Nidorino on the title screen as a kid. Then when we and my friend used to play Gold and Silver we both liked Ampharos. Then at the same time I was like <3 Tyranitar looks way cooler then anything thus far, love the design love move pool, great stats win win win for me. Then when I saw Blaziken in the Silver Conference I was like "Wow what a badass pokemon this thing is without a doubt my favorite starter of all time, I also liked Shiftry Tengu design that gen as well as many others. Gallade just seems like a awesome pokey from the get go with an awesome typing, alright movepool. As for 5th gen I like Braviary, Bisharp, Volcarona, Haxorus, Hydregion, Mienshao, Golurk, Carracosta, Krookodile, among many others. How about yourself?
Also I probably won't be swapping much any more since I already mentioned I probably wouldn't go hard for it. So when you need some swaps just vm(even though I will probably do a few every now and then.