I like 'genus' too. I was lucky enough that Marshal and Lucky both asked to call me that so I happily agreed. Much better than them calling me lollipop before.
If you say no sometimes they'll ask you what you want to be named in return and than you can give them nicknames that represent their personality without it seeming stupid. Some of the names are horrible and NL wasn't any better. I used to tell them what to call me on that game to.