San Ramon de Alajuela is a fantastic place to make your home base to see much of Costa Rica.  Many places will offer you a free night on a weekly rental so being able to leave your things while you take an overnight trip won't feel Ike you are paying double!  It's a tico town but wiith all the amenities of a larger city ... Just without the crime and the crap.  Almost garbage free, this City of Poets is tranquil and relaxing.  Stay in town at one of the hotels, or better yet, venture to one of the mountain top b&bs overlooking the mountains and the Pacific Ocean.  As the clouds literally roll in through your open door, you won't get a more unique experience.  

Day trips can easily be made to the following tourist attractions:

punterenas (can take the ferry to the Nicoya peninsula) 

Poas Volcano

La Paz waterfall gardens

arenal volcano and hot springs ... NOT EL CASTILLO... That is on the other side of the volcano and require at least an overnight if nt 2 nights

Sarchi (famous for the Oxcart)... And check out else kientzler botanical gardens in Sarchi Norte 

San Jose city ( the capital-visit barrio Amon, the opera house, the gold museum, the children's museum and the central market) 

Los Angeles cloud forest... No need to travel to Monteverde ... there is a cloud forest right here!  

Nectandra gardens... Another cloud forest reserve right here in San Ramon (favorite)

Museo de san ramon

la feria outdoor farmers market on Friday and sat... Kick walmart to the curb and get everything you need here fresh from fruits and veggies to cheese and chicken  (yes, Walmart has made it here to Alajuela... Near price smart, aka cosco) 

las Musas waterfall and pools (swimming pools are concrete but the water is from the gorgeous falls)

biking, hiking.... in the central highlands!