I had a good time using Ampharos in White2, and always go drudging through the earliest cave available in the Unova region to get myself a Drillbur to evolve into Excadrill. It's that good to me. (and well-suited for wrecking Elesa) I love Aggron despite being slow and clunky and...
I legit leveled my Scyther all the way up thinking it would evolve in a Scizor, consequently being quite dissapointed when I had a level 100 Scyther in the end in my original Silver run as a kid. The same thing applies to Raikou and Suicune in particular, as I adored the rare Raiko...