Must-visit in Quito!

[Moderated]

In no particular order:
1. Basílica del Voto Nacional (climb the clock tower)
2. Oswaldo Guayasamín Museum
3. Go up the Teleférico (if the weather is clear)
4. Walk around the plazas and cathedrals in the Historic Old Town
5. Visit the Mitdad Del Mundo

Number 5 isn't that exciting, but it's somewhat obligatory being that Quito is so close to the equator.  Some notable mentions are:
Carolina Park,  It´s a very pretty park and is great for people watching.  It also has a really nice botanical garden.

Bella Vista park is also very nice for a walk and it´s huge.

Take a taxi up to La Virgen del Panecillo.  There´s not much to do up there except look at the city and the statue up close, but it's a memorable experience.

The market in La Mariscal Sucre, especially if you´re not going to Otavalo.  It has a lot of similar indigenous arts, crafts, and textiles.

Daily Tour Buses in Quito. March 2012.

Since December 1st, 2011, Quito has double-decker tour buses for around-town tours. Every day at 9 a.m., 10 a.m., 11 a.m., 12 p.m., 1 p.m., 2 p.m., 3 p.m., 4 p.m. you can buy tickets and board the bus.  Here is where you do it - go to Centro Commercial Inaquito (corner of street Amazonas and Nacional Unidas). Turn your back on Amazonas and walk on Nacional Unidas toward Shyris. There is a bus stop there (before Shyris) and next to it - little red bus kiosk where you can buy tickets to the Quito tour bus and board it there as well.

Ticket cost $12 for adults, $6 for kids, seniors, and disabled.  Duration of route is two hours and 45 minutes. You can get on and off to check points of interest

Paradas (stops)
I Parada Boulevard Naciones Unidas (LB -good point to board bus)
II Parada Jardín Botánico - parqueadero de La carolina
III Parada Mariscal - sobre Av. Amazonas y Calama.
IV Parada El Ejido - sobre Av. Amazonas y Av. Patria, frente al hotel Hilton Colón
V Parada Centro de Arte Contemporáneo - ubicado en el barrio de San Juan
VI Parada La Basílica - calle Matovelle (LB - out to check Basilica)
VII Parada La Compañía - frente a centro comercial Amador (LB - out to check Compania and Old town in general)
VIII Parada Panecillo (LB  -out to check Panecillo)
IX Parada Av. 24 de mayo - calles Venezuela y Loja
X Parada Plaza Grande
XI Parada Parque García Moreno - calle Vargas.
XII Teleférico – en la Av. Occidental  (LB - out to check Teleferico)

Daily Tour Buses in Quito. March 2012.
more info here
http://www.quindetour.com/