What is/are your favorite instrumental solo/solos in a non-concerto piece?

I'm amazed that I'm the first person to mention Rimsky-Korsakov's 'Sheherazade' with its almost-concerto violin solo. I actually love the many long woodwind solos which Shostakovich inserted into many of his symphonies:

Symphony No 4 - bassoon (first and last movements)

Symphony No 6 - cor anglais (English Horn in American)(first movement)

Symphony No 7 - bassoon (end of first movement)

Symphony No 8 - cor anglais (heart-breaking solo towards the end of the first movment)

Symphony No 9 - bassoon (the whole fourth movement)

Symphony No 10 - clarinet (2nd theme in first movement)

Symphony No 11 - cor anglais (near end of last movement)

As well as the horrifically difficult trumpet solo in the middle of the third movement from Symphony No 8. The cello solo in the second movement of the 15th Symphony is worthy of a concerto slow movement.

I also love the virtuoso first clarinet part in Bartók's 'Miraculous Mandarin' and in Kodály's 'Dances of Galánta'. There is also a delicious clarinet solo in 'Winter' from Glazunov's ballet 'The Seasons'.

I concur with the two Rakhmaninov offerings - I adore that trying-to-be-slightly-jazzy saxophone solo in the Symphonic Dances (his best work in my opinion) and would add the gorgeous horn solo at the beginning of the slow movement of the Third Symphony. This solo really needs a thick, vibrato-ed horn in the old Russian style to make it sound as I believe Rakhmaninov envisaged it (despite his living in the USA by this time). Svetlanov's recording really does this part justice for me.

It might surprise some regular long-time contributors to lean that I also enjoy the oboe solos in the slow movements of Brahms' Second Symphony and Violin Concerto (surprised because am I no fan of Brahms).

I will probably think of more later and I will add them as edits if I do so.

I like the oboe solo in the first movement of Ottorino Respighi's Pines or Rome, even though it isn't that long. It fits the piece really well.

Wow, you took the words right out of my mouth with the Saxophone solo from the Symphonic Dances. How saxophone solo that transforms into the soaring melody in the strings... absolutely amazing.

I really like the flashy violin solos in Rimsky-Korsakov's "Capricco Espagnol," as well as the cello solo at the beginning of Sibelius' tone poem "Pohjola's Daughter." It's so deep and wintry. It makes me want to go to Scandanavia haha. Check it out: http://www.youtube.com/watch?v=ZtB0ZRKSnLs

I adore the rapturous clarinet solo in the opening of the 3rd movement (adagio) of Rachmaninoff's 2nd symphony. Truly ethereal!