Elextricin

They seem like a similar size as the BMW 5-series and MB E-Class but those are the GS's competitors and the GS is priced more similar to the E-Class and 5 Series too.

And i'm familiar with the BMW 3-series and MB C-Class but those are definitely the IS's competitors since they are both smaller and sportyish.

So what does the ES compete with?

sford52

I would guess these might be considered competitors:

Buick LaCrosse

Nissan Maxima SV (very sporty, but...)

Lincoln MKZ

Cadillac CTS

I'd include the Buick Lucerne if they still made it.
Don't know enough about Accura, BMW, etc to say anything

SW17LS

Used to be the ES didn't have a lot of competitors, but its a little more crowded nowadays. What I always liked about the ES was that you got a 5 series sized car for a 3 series price.

Nowadays the competition is the Avalon, Buick Lacrosse, Lincoln MKZ, Hyundai Azera. To a lesser extent the Hyundai Genesis, low optioned 5 series, CTS.

Mater17

Acura TL, Infiniti G Sedan, Audi A4, Volvo S80, MB C-Series

WheezerMF

+1 for Mater17. I guess I'd throw the Maxima and Avalon into the mix, too, since they're higher-line cars from lower-line marques.

Trexus

The ES is a unique luxury model. When it first arrived the main competitor was the Infiniti I30 but Infiniti discontinued it leaving the ES in a class of it's own.

Currently the ES competitors are the Acura TSX V6, Cadillac CTS, Lincoln MKZ.

Now the ES has expanded:

ES 350
ES 300h