I prefer Latino since the language my family speaks comes from Latin, but beyond that my family's ties to Spain are long gone. Hundreds of years gone, just like my American family's ties to Britain.
Whenever the subject of ethnicity comes up I like to mess around with people and tell them I'm a True Latino on my mom's side. Both of my mom's parents came to the US from a couple small villages in Lazio, which is the homeland of the Latins, and so I always say I'm a real Latino unlike all those fake ones from Mexico.
Yeah that's many centuries removed from the original Latin tribe so she's probably not really an ethnic Latin, but I always get a kick out of the confusion on people's faces when I say that, especially considering I look like a stereotypical Irishman with auburn hair and freckles (my dad's side of the family is mostly Irish). Most people who put a ton of stock in that kind of thing are typically liberals and relatively uneducated about history so its always good for a laugh.