Besides the family/clan tartans, there are district tartans, including Irish County tartans. If you have an idea of what region your family was from, those might provide a nice connection. There are also the fashion/universal tartans, like "Pride of Scotland" and so forth; these might be good choices for you. Or there are USA Kilts has some nice registered tartans for Americans, people with German in their background, firefighters, or people who are Mary Stewart available; these sorts of things may appeal to you.

The tartan of one of the Highland regiments may appeal, if you either had an ancestor who served or simply have a respect for these fighting men, in which case you may want to wear Gordon, Black Watch, Seaforth or another.

Find a connection, of heritage or interests, with a group that has a tartan of its own, whether clan, society or whatever, and you'll have a kilt that means something to you.