Wich is the most beautiful beach on west coast of ecuador?

I think it's Esmeralda, been there once and it was breathtaking.

Banos is the biggest one on the west coast. I am not sure what beaches they have on the "east coast".

About 20 to 30 minutes to the south of Manta there is a small town called Santa Marianitas. This is one of the best beaches I have seen in all of Ecuador's coast. It is a very long beach with a few restaurantes and even a small hotel with a swimming pool. They have kite surfing during the summer months on weekends.

Los Frailes - considered one of the best beaches on the entire South American Pacific Coast.

It is South of Esmereldas in the Province of Manabi.

Selenas is a lovely beach and seaport, the water there is so clear! And I have to say Santa Mariannita is a beautiful beach and they are opening up little restaurants and hostels on it, Very convenient. Another place to go is Montanita. It's so beautiful and is very hippy-ish, many tourists/surfers from Europe usually go there. Most beaches on the scenic route or "Ruta Del Sol" are gorgeous, natural and haven't been exploited! Enjoy =]

BAGOFSWAGS has no idea what he's talking about. Ba帽os is not a beach. It is a small town on the east side of the country, close to the Amazonic region.
Ecuador does NOT have an East Coast.

To answer your question, my favorite is Monta帽ita, and a small beach named Pacoa. It is 40 minutes north of Salinas. Pretty close to Monta帽ita. In the province of Guayas.

Atacomes is beautiful with very interesting night life, I went there twice when i was in Ecuador for 5 weeks in April/may it was so good the fisrt time I had to go back

I have been to Ecuador twice and traveled the coast pretty extensively. While most of the beaches that others have mentioned are very beautiful, the place I found the most beautiful was a pretty secluded beach, Mompiche. I did hear that the country had plans to develop the town, as of now, it is still very isolated. I walked for miles on the beach and the only people I ran into were some children who were gathering coconuts.

Here is a description I found online:

Mompiche is located on the northern Ecuadorian Coast just south of Muisne in the Esmeraldas province, is one of the most extraordinary nature , his impressive waves, beautiful landscapes and exquisite food, they it do the ideal site to enjoy of a perfect day of beach.

Mompiche is covered principally by humid forest always green of low lands, which it reaches 300 m of altitude. Mompiche's beaches, it is the new magnet of the national and foreign tourists.

Mompiche is a town of 150 houses of cane and wood where the majority of the settlers devotes herself to the fishing, nevertheless from 2001 some families overturned his interest for the tourism and initiated the constructions of cabins and restaurants, Shrimp fishing and tourism are the two most important activities of the community.

It is the ideal place for the lovers of the surf. Mompiche is one of the last humedales-marine woods nearest to the bark of the Ecuador. The place has been kept enough good with species of fauna and flora.

Mompiche ranks among the most idyllic, unspoiled beaches on the coast, little more than a sprinkling of huts and fishing boats.

Only a few minutes from the Mompiche beach and near the Mache Chindul reserve, is the mangrove region and dry forest area in which you find trees such as bay leaf, balsa, pacas, oak, guayacan and ebony, which are inhabited by howling monkeys, aardvarks and badgers.

The coast of Mompiche has so much to offer in terms of surfing, exploring, whale watching, fishing. A very centralized area for surfing is "Low headland".