I think it was the penultimate team because the final team didn't encounter all of the Vale of Vanburn. (I wonder if it was cut to make time.)

Martin's team were the penultimate one, and they met an imprisoned Velda in that room, whom they set free with a key from the clue room. No spidey.

The final team were, as I recall it, the only team to go through the cave in the middle of the VoV; they were being chased by goblins from both behind and in front of them. After hints from Treguard they took that exit, went through the corridor of the catacombs, and emerged back at the 'waterfall' end of the VoV, where Hordriss chased off the goblins with a magic sword.

Ariadne's layer from series 2

...was changed quite a bit since in series 3 it becomes the entrance to the Vale of Vanburn, and Ariadne is no longer there.

(By the way, it's "lair", not layer - this needs correcting throughout the series guide, too...)

In Series 2, the teams used this room to choose a path.

Finally, it is used in series 3 with the Giant's foot behind it

Well rooms

ledge rooms

Falling Bridge (?)

Mine entrance

room with the maggots

The inside of the snake/monster was reused in S2 and S3, Lilith's lair was changed to include the moving tongue and the wellway room is pactically the same.

Block and Tackle

I know this appeared in Series 5, but I really do think it counts as a major change rather than a minor one - there were no moving blocks, nor was there a disappearing floor

As for any others...

The rooms with the gargoyles in

The room with the catacombite in (s1t6 and s2t4)

The kitchen (although it gained more actual furniture, and lost some CG stuff)

The level 3 entrance room (essentially the same for the first three series)