This is a list of scenes from different episodes that are 'shipper-y'. They may contain UST or simply a nice shipper moment.
Their meeting in 'We The People'
The sibling comment in 'Washington Holiday'
The teasing between Mac and Harm (dressed as a gunny) in 'Force Recon'
The Halloween moment in 'Vanished'
The final scene in 'Impact'
The dinner scene in 'Father's Day'
The hugs in 'Black Jet'
The apartment scene in 'The Martin Baker Fan Club'
Chloe's introduction to Harm in 'Jaggle Bells'
The talk about flying in 'Shakedown'
Harm convincing Mac to see her father in 'Second Sight'
The parallels between Mic/Mac/Harm and the kids in 'Into The Breech'
The agreement in 'Yeah, Baby'
The end scene of 'Goodbyes'
The 'there's someone you want to be with but can't' speech in 'The Witches of Gulfport'
The kiss on the boat in 'Ghosts of Christmas Past'
The final scene in 'Surface Warfare'
Mac following Harm to Chechyna in 'Legacy II'
The Mac and Kate conversations in Touch and Go'
The final scene in 'Touch and Go'
Harm's reaction to the engagement
The teasing friendship in 'Baby, It's Cold Outside'
The fantasies in 'Retreat, Hell'
Harm's attempts to talk about the kiss in 'Mutiny'
The beginning of 'Adrift I'