For those thinking about plane+car
Barcelona-Valencia are 350km, very good highway but tolled, according to ViaMichelin are 36euros.
By train,not high speed but very good too. with Renfe. Cost from 40euros, takes at least 3h.
some trains arrive to Valencia-Nord some others to the nearby high speed trains and alike station Valencia-Joaquin Sorolla.
By bus with Alsa takes 4h cost 27euros.
Madrid-Valencia are 350km, first half of highway, lots of traffic and not very good. Second part, with less traffic and much better. Toll free.
by train, high speed with Renfe. Arrives to Valencia-Joaquin Sorolla station.Cost from 70 euros, takes 1h38. or more. Probably not any offer available for fallas dates.
By bus with AvanzaBus takes about 4h15 and from 28euros.
Alicante-Valencia, 170km, very good higway but depending on the route chose, with tolls.
By train, good trains, not high speed but close, takes from 1h30. some trains arrive to Valencia-Nord some others to the nearby high speed trains station Valencia-Joaquin Sorolla.
Cost about 30euros.
by bus with Alsa Takes 2h30, cost 20euros