I am very fond of the six symphonies of the Czech Bohuslav Martinu (1890-1959). They comprise the most consistently uplifting cycle of modern symphonies, being full of hope and warmth of feeling. The first five came at yearly intervals beginning in the darkest days of the Second World War (1941), just after the composer had emigrated to America, and all ache with longing for his Czech homeland.
The whole cycle (which ended in 1953) does feel remarkably homogeneous. The symphonies may take many an unexpected harmonic turn and can, especially in the Third Symphony, venture far into chromaticism, but they remain strongly tonal in orientation and have a delightful habit of breaking into Bohemian/Moravian-style folk melody and/or into radiant lyricism. They tend to grow from small motifs (or cells) which are then evolved into broad symphonic paragraphs. They also share motifs associated with the Czech lands - phrases drawn from the St. Wenceslas Chorale and Dvorak's Requiem (the opening notes) and, most obviously, an 'Amen'-like cadence called the 'Moravian cadence' (a variant of the plagal cadence) which was invented by Janacek in his glorious Taras Bulba (you can hear a sequence of them in the great passage beginning at 5.04 in the linked video) but which Martinu very much made his own. The symphonies are full of the composer's trademark syncopated 'sprung' rhythms. These give the works a real spring in their step. They mix (in their own individual ways) tension and hope and the time-honoured symphonic struggle between darkness and light is fought (in their own individual ways) throughout all of the symphonies. The even-numbered symphonies are generally brighter in mood, with the odd-numbered ones pursuing more troubled paths towards resolution - though the Sixth seems to unite the best of them all. The works are all scored in a way that can only be described as luminous. Only the Sixth Symphony - excludes the use of a solo piano.
I hope you will enjoy exploring these delightful symphonies.
Symphony No.5 (Mts.2,3,4)
Symphony No.6 (Fantaisies Symphoniques)