I thought I'd post something about seasons. Season 5 had widely been touted as one of the most exciting seasons of Doctor Who. It's also the first full season to feature Patrick Troughton, as the regeneration appeared part way through season 4. I may be wrong but the only other time I believed it happened is when Peter Davison regenerated into Colin Baker.
Anyway Season 4 sees the Doctor saying goodbye to Hartnell era Ben and Polly and new companion Victoria emerging in the season finale The Evil of the Daleks.
That turned out to be the last appearance of the daleks until Pertwee became doctor. The feeling was they'd been overused and needed a break with different monsters.
That's what season 5 delivered.
Tomb of the Cybermen.
The third encounter with the cybermen following Hartnell in 10th Planet, which was his last adventure, and the Moonbase which was Troughton's 4th adventure. This is really good with a sense of lurking menace as the cybermen slowly start coming back to life. There's also a good comic scene where Jamie and the Doctor inadvertently hold hands. And all episodes are available.
The Abominable Snowmen
The first encounter with the yeti, controlled by The Great Intelligence, played much later on by Richard E Grant in a Christmas special which turns out to be a prequel to this episode.
It's set in a Tibetan monastery the Doctor has visited before, but things aren't right. The normally friendly monks are quite hostile and the usually quiet and timid yeti have become very violent.
Episodes are lost, but it has been novelised and audio versions are available.
The Ice Warriors
First encounter with these chaps in the frozen future. It's another ice age with scientists using a massive heat ray to keep the ice in check. The someone discovers a frozen body which turns out to be an ice warrior. The leader looks the same as the rest, making him stand out came later.
All episodes are available but two have been animated.
The Enemy of The World
The only non monster one but an enjoyable romp set in 2018 where the Doctors double the evil Salamander is set to take over the World. Interesting to see what they got right, not much. No internet but you can travel around the world by rocket in less than an hour.
All episodes available.
The Web of Fear
The yeti again, this time in London. Noted for first appearance of Lethbridge Stewart. The Great Intelligence wants the Doctor's brain.
One episode missing played with full dialogue and still from production. All the rest are fine and it's really good.
Fury from the Deep
Last episode with Victoria, something nasty is lurking under the North Sea interfering with the gas lines.
The Wheel in Space
Cybermen again, first appearance of Zoe. This is set on a space station where crew keep disappearing, a favourite tactic of the cybermen, prior to invasion of Earth.
This is currently unavailable but is the next story due to be animated. It was supposed to come out in November and it can be pre ordered on Amazon US, but no dates yet.
Link to more detailed episode guide.