Oh, I'm so predictable. My friends pick on me all the time as to how often I use the same Pokemon in every team.
Kanto: Fearow, Raichu/Magneton/Electrode, Lapras, or Blastoise
Johto: Crobat, Miltank, Dragonite, Espeon, or Feraligatr
Hoenn: Gardevoir, Azumarill, Aggron, Breloom, Skarmory, Hariyama, or Blaziken
Sinnoh: Toterra, Empoleon, Staraptor, Drifblim, Roserade, Ambipom, or Pachirisu
Unova: Jellicent, Stoutland, Simisear, Emboar, Swoobat, or Musharna