My clan is O'Callaghan, on my mother's side. There are only about 20 recognised Irish clans, and about 10 times that number of Scottish ones, but O'Callaghan is one that the Irish government has recognised. There is a corresponding tartan, although it is not recognised by the chief, neither is it atall old, and nor were Irish kilts traditionally tartan anyway, but solid colours instead. On top of all that, the Callaghan tartan is a special order weave. It's quite nice looking, though, and I would wear it if I could justify the cost.

I have Irish district and solid colour kilts rather than a Callaghan kilt. It's cheaper that way.

My wife belongs to the Scottish clan Davidson via her maternal grandmother. I suppose I could wear her tartan. I like the ancient version because the modern is too dark, IMHO.

My father's mother was a Hart, and there is a Scottish tartan associated with that name, although it is not actually a clan. I also have an aunt in that branch who married a Scotsman and became a Guthrie, and they have a clan tartan, but I'm not descended from them.

I have Gunns in my family tree, but they were Irish. Although I hear that clan Gunn will take anybody I'm probably not really connected to the clan.

If I added all the names in my family tree that are on Scottish sept lists I could come up with another half dozen Scottish clans, but the connections are all dubious.

As for a favourite, I'm not sure I have a favourite tartan.