Depends on your pronunciation, I guess. In the written picture "ego" is the better rhyme. I don't know if there is a sanctified Egnlish pronunciation for "Lego", after all it's a Danish company. In my mother tongue, my rhyme would be the better one - pronuncitation of foreign words like written."Lego" is Danish and Latin (1st person singular presence of "legare" ), and "ego" is Latin, both are pronuciated with a reatlive long "e, "eggo" would be pronunciated with a very short "e", like in "beggar"). But maybe in the US people think more of "leg" when they think of "lego" (hardly any one knows Latin, anyway), so the average person might pronounce it similar to "eggo".