M-Audio's popular Axiom series of keyboard controllers comes in different sizes and with some nifty included software, too! G. W. Childs gives the 61-key version a thorough work-out in this review.
Many musicians have a MIDI Synth lying around gathering dust. Still in love with its analog sounds? Want to sample its sounds into your software sampler? Redmatica's AutoSampler 2 holds the key.