I have been wanting to go to Germany for years. I even began learning German on my phone via Duolingo and once the ticket was booked, I promptly stopped...
The first order of business was lunch at House of Small Wonder - read more about it here.
Brandenburg Gate was the first stop, where I finally had to swap memory cards. Sadly, the nearby Reichstag roof was fully booked during our time here, but I highly recommend going. Just remember to book in advance!