The Two Doctors is a really good Doctor Who serial. the second Doctor (Patrick Troughton) and the sixth Doctor (Colin Baker) cross paths and end up stopping the Sontarans and some Androgums from getting the key to time travel.
I love these team ups, and it's probably a good thing they are rare, since doing it all the time would take the specialness out of it.
I don't know much about the sixth Doctor, as I've only seen a few of his adventures, but I am looking forward to more of them. because they were the only two Doctors present, and only had one companion each (Peri and Jamie McCrimmon) we get more time with them than the other two multi-Doctor shows. and the wordplay of the Sixth Doctor was really good, mixing personal pronouns and all.
however, how come the sixth Doctor didn't remember this meeting? does regeneration leave your memory swiss cheesed?