My favourite mission is the last ''Zeratul mission'' where you have to defend until the last man, seeing all the hero units die is quite sad especially Artanis in the purifer. I basically just spam carriers and build tons and tons of cannons with some support from high templars with psi storms.

" My favourite mission is the last ''Zeratul mission'' where you have to defend until the last man, seeing all the hero units die is quite sad especially Artanis in the purifer. I basically just spam carriers and build tons and tons of cannons with some support from high templars with psi storms. "

Definitely the day/night cycle one, but the train robbery one was also pretty neat. 
 
Defending with the Protoss was awesome because I managed to stay alive looong after I needed to, but since I was playing on normal difficulty that wasn't enough for the final achievement. 

" @RelentlessKnight said:

" My favourite mission is the last ''Zeratul mission'' where you have to defend until the last man, seeing all the hero units die is quite sad especially Artanis in the purifer. I basically just spam carriers and build tons and tons of cannons with some support from high templars with psi storms. "

That was actually my least favorite mission of the campaign.  I hate missions that are just defend your base. My favorite is probably the last Tosh mission if you side with Nova instead of Tosh. "

" Definitely the day/night cycle one, but the train robbery one was also pretty neat.  Defending with the Protoss was awesome because I managed to stay alive looong after I needed to, but since I was playing on normal difficulty that wasn't enough for the final achievement.  "

Day and Night Zombie missions.

" Day and Night Zombie missions. "

The laser one, that was awesome. Got all 3 achievements on it without even knowing what they were.
 
Least favorite must be the Odin one. Idiot Tychus, let me macro up you asshole.

My favorite was the Odin one, was real fun having to follow him around. :)

Nova

I'd say destroying the Nydus Canals. As for the zombie mission, it's completely broken if you have reapers.

Nova!

Zertual's last mission and the Zombie one on hard.  It was super fun going for the achievement on hard.  Took like an hour to do.

" Nova! "

The only one I disliked was the one where they introduced the Banshee, because that maps basically forces you to do nothing but mass banshees on hard and brutal. 
 
My favorite mission was the last one, especially because I forced myself to get the achievement for Valerian's profile pic. So I beat that mission using the artifact only once. That was cutting it REAL close. I had 12 marines and 2 medics left, going from 99.5% to 100%.

'In Utter Darkness' (the final protoss mini-campaign mission) is extremely epic.
  
I always had a soft spot for 'last stands' ala 300.