My husband got me an Ultimate Sweater machine for Christmas last year. It defaults to making things with stockinette stitch, and you can easily enough make stitch patterns with a knit- and purl-side: cables, entrelac, a number of laces. For garter stitch and ribbing you have to drop stitches and use a crochet hook or a latch tool to latch them back up in the pattern you want.
It holds up to 100 stitches without an extender kit; I've used it to make scarves and a very simple sweater.
It's got a bit of a learning curve; for a while, I dropped tons of stitches. Once you get the hang of it, though, it's entirely possible to pop out a double sided, 6 foot scarf in about two hours.
I enjoy it for things with simple stitch patterns and simple stitches. I think it's a pretty decent first knitting machine, though now I think I would like something a little fancier.