Mirrorcle World. I guess that's cause I knew her right after the single came out, and it really made an impression on me.

SEASONS or evolution hands down...I see both of those as her iconic "Ayu" song

SURREAL, and sometimes Lelio or Bold & Delicious for who-knows-what-weird-reason :tipsy

I would say either M, SEASONS, or Voyage. Those seem to be the ones everyone knows, so it's hard to go wrong with those when I first introduce her to someone.

Out of the three, I think M (from I am...; with the electric guitar interlude) provides the best impression since it sums up her musical style pretty well even when you include the past couple albums, like mi|kshake said.

Dearest... :love

Appears, To be, and a few others...which is funny since those aren't necessarily my most favorites of hers... OH and Who...

M is perfection.

SEASONS

kyou ga totemo tanoshii to asu mo kitto...

Moments :)

No more words. :love

Evolution. :)

Boys & Girls, SEASONS, Dearest, Voyage, BLUE BIRD. You know, the classics that most people adore.

evolution and M, my early favourites.

M or SEASONS.

A Song for XX or Who..., mainly
Also: Dearest, M, Endless sorrow...
It's so hard to name just a few ones! :laugh

M, Depend on you, Fairyland, HEAVEN, SURREAL - They remind me of when I was 14/16 yo

Mirrorcle World, Love song, Sparkle, Microphone.

Evolution.
This is what started the madness! lol

SEASONS is the first song that comes to mind.

Evolution for me, that was my first ayu encounter.