From your list I like [name]Brett[/name] [name]Andrew[/name] or [name]Brett[/name] [name]Michael[/name] best. Something more classic to go with a name that held more popularity in the 80s, but is still strong. [name]One[/name] thing to consider though, what initials could spell with a middle name starting with a vowel (i.e BAD, [name]BAT[/name], BIT, BOD, BOO, etc.)
I think mn’s beginning with consonants flow better with [name]Brett[/name] ([name]Brett[/name] [name]Jacob[/name]/[name]Peter[/name]/[name]Michael[/name]/[name]David[/name]). I like [name]Alexander[/name] but a vowel mn blends into [name]Brett[/name] (Brettalexander, Brettisaac etc…). I like longer middle names with the one-syllable [name]Brett[/name].
Of your list I like [name]Brett[/name] [name]Alexander[/name]. I think mostly because [name]Alexander[/name] has more than one or two syllables. I also like [name]Brett[/name] [name]Nathaniel[/name] that mischa posted for the same reason I think. They have a nice flow.
Good luck!
I like [name]Brett[/name] [name]Collin[/name] and [name]Brett[/name] [name]Oliver[/name] the best, but [name]Brett[/name] [name]Collin[/name] is my favorite. Mishca’s suggestions of [name]Brett[/name] [name]Emmanuel[/name], [name]Brett[/name] [name]Malachi[/name] and [name]Brett[/name] [name]Jonathan[/name] are nice, too. I really like the name [name]Brett[/name].
I’m really liking [name]Brett[/name] [name]David[/name]. When I glanced at your list, that is what stood out to me, so I’m going to go with my first impression. =]