Which couples comes in your mind when I say:

Epic: Uther/Morgana (Merlin BBC)
Meant to be: Arthur/Gwen (Merlin BBC)
Pointless: House/Cuddy (House MD)
Overrated: Damon/Elena (TVD)
Sweet/Cute: Castle/Beckett (Castle)
Funny: Lily/Marshall (HIMYM)
Tragic: Willow/Tara (Buffy tVS)
Underrated: Buffy/Giles (Buffy tVS)
Hot: Gretchen/T-Bag (Prison Break)
Amazing: Clark/Lois (Smallville)
Terrible: Olivia/Peter (Fringe)

OTP: Gretchen/T-Bag (Prison Break)

Epic: John/Aeryn (Farscape)
Meant to be: Jack/Sam (Stargate SG-1)
Pointless: Mac/Peyton (CSI:NY)
Sweet/Cute: Chuck/Sarah (Chuck)
Funny: Niles/CC (The Nanny)
Tragic: Adama/Roslin (BSG)
Underrated: Doug/Carol (ER)
Hot: Sam/Jules (Flashpoint)
Amazing: Peter/Olivia (Fringe)
Terrible: Ziva/Ray (NCIS)
OTP: Tony/Ziva (NCIS)

Epic : Ross & Rachel
Meant To Be : Lexie & Mark
Pointless : Rachel & Joey
Overrated : Damon & Elena
Sweet/Cute : Callie & Arizona
Funny : Marshall & Lily , Sheldon & Amy, Howard & Bernadette, Phoebe & Mike
Tragic : Alex & Izzie (tragic end), Alex & Lexie (tragic couple)
Underrated : Niles & CC
Hot : Lucas & Brooke, Jackson & April, Nate & Serena
Amazing : Piper & Leo
Terrible : Dan & Blair
OTP : Monica & Chandler

good question!!

epic: অ্যাঞ্জেল & Cordelia (Angel)
meant to be: Jim & Pam (the Office)
pointless: Buffy & Riley (B.t.v.s.)
overrated: Damon & Elena (the vampire diaries)
sweet/cute: Marshall & Lily (himym)
funny: Chandler & Monica (friends)
tragic: Izzie & Denny (grey's anatomy)
underradet: Abby & Jimmy (harper's island)
hot: Spike & Buffy (B.t.v.s.)
amazing: Phoebe & Cole (charmed)
terrible: Lucas & Peyton (OTH)

OTPs: Pacey & Joey (DC) and Rory & Jess (gilmore girls)