Lol, I was going to say Aegis-class b/c of how many were on loan to the Falcons initially and theirs later on- though I am not sure that ever was properly resolved in unit counts.
Then . . . for Clan warships that got mention . . . off the top of my head-
Dire Wolf- de facto Invasion flagship along with Wolf flagship, participated in the Refusal War and then dropped from sight
Werewolf- Warden flagship, involved in the invasion of Tharkad w/capture of Mjolnir, participated in rescue out Outreach, and other actions before the Jihad purge
Emerald Talon- in the background of the Invasion & Refusal War, participated in Jihad?, Op Icestorm, the DA Falcon desant . . . until Malvina dropped it on the Falcon council
Ursa Majoris- background of Invasion (bid away at Rasalhague?), involved in defending Alshain from Black Dragon attack, part of the Trial WWE?
Kerensky's Blues- BSI took the Fredasa from the Falcons, limping repairs, involved at invasion of Tharkad, finished by Falcons
Osis Pride- Met retreating Hellions besides playing ghost ship of the Periphery
Streaking Mist- Lincoln Osis ride, joined the Jaguar later on, fought fleeing Scorpellions over a Blakist cache