Orchestra samples are generally very expensive to buy, but the UK’s highly regarded Philharmonia Orchestra has a gigantic royalty-free database for download at its website. It’s not just string sections either – it covers everything from the French horn to the Thai gong. So if you want to make an epic record, like Kanye’s Dark Twisted Fantasy, or layer your soft synth patches with organic instruments, then this could be a useful bunch of samples.
PS. The Philharmonia Orchestra is not just any old orchestra by the way. It was founded back in 1945 by EMI producer Walter Legge and during its first seven decades, they have collaborated with most of the great classical artists of the 20th century. So this download one is quality!