The DOA5LR launch trailer OST and maybe Shiden's Dimensions theme xD Kasumi Alpha's Dimensions theme is a close third for me
Free Step Dodge
KasumiLover
NewWestFan
I'm hoping for Power is Beauty and B-Boy No "B" Lmao though I know they probably aren't iconic enough for most people. But when I think of DOA they're the two songs in my head.
Force_of_Nature
Aerosmith's opening theme to DOA2U (Dream On) and DOA4 (Eat the Rich). Other than that? Nothing really apart from Bankotsubo's DOA2 theme, since DOA5LR had almost all of DOA's themes.
KasumiLover
Are those DOA1 tracks? I'm hoping that all tracks for all the games are in tbh but if they do feature some tracks as DLC I would pay for Dimensions and remix themes tbh too xD
NewWestFan
Power is Beauty is Tina's theme from DOA1 and B-Boy is Zack's from 2 iirc. But honestly hopefully they give us two really badass new songs.
VAND1TA
Both DOA2 ost, Vigaku and The shooted
NewWestFan
Vigaku is pretty iconic to me too yeah. And Blazed up Melpomene.