It's not uncommon for Reanimator to board in Show and Tells when faced with graveyard hate. The only issue is that you end up being half of a Reanimator deck and half a Show and Tell deck. Is it correct to discard that Griselbrand to Careful Study on turn 1, knowing you might draw Show and Tell later?
Once you have the Show and Tells and the City of Traitors that help you get to three mana, or give you extra mana to help play around Daze and Spell Pierce, your sideboard tends to be a mess after that. I guess you could sideboard Pithing Needle or Echoing Truth to fight hate even further, but that certainly dilutes your deck. It's also a pretty big risk to bring in cards to answer things they might not even have in the first place.
Instead of trying to sideboard answers to their answers, it might be best to sideboard into a completely different deck that they aren't prepared to fight, and I think War.MasteR. did a good job of crafting his sideboard to do that. Reanimator is a known quantity, but its explosiveness is what allows it to keep winning, especially since it's basically the anti-combo combo deck. If you could craft a sideboard to fight the hate, who knows how good Reanimator would be.