I feel like it's almost a cliche to use one of these little multitracks like the Tascam Porta02 MKII now, but they're just so much fun. It's cheap for what it can do, sturdy, and I can't recommend it enough. I've lost hours sitting in front of this ugly little box finding new things and I really think I'd be way more sonically boring without those hours I've spent.
It's overflowing with beautiful sounds, relatively simple to tweak, and just an endless source of inspiration. There's a reason the MicroKorg is the most ubiquitous little synth in indie music.