Gotta go with Ol' Lee on this one, bud. While I like the concept of high tier characters duking it out for eternity, Lina Inverse isn't exactly tipping the scale in that direction.

Edit: I can understand why you may be confused, what with her having a 'city busting' attack and all, but that's because a single ability with city-wiping potential(unless it can be used pretty often) doesnt make her the most powerful at any table of powered monsters, errant godlings, saiyans, superman etc etc. Not even close if we're including people like supes on the roster... Who can sleep inside the sun.