I don't only wear knit ones, but sewn ones out of lightweight knit fabrics. I have two favourite styles - basic ones that button up the front, and a more drapey style, with no closures, but more fabric and a longer tail at the front.
Here's my go-to black one - I think I paid around $20 for it, and wear it often - usually with a black tank top and black cargo capris or shorts.
I took it and drafted a pattern for it (ugly Christmas wrapping paper makes great pattern paper).
Then I cut out some fabric I had bought, sewed it up, and here's the result:
One thing about this fabric - it was full of sizing when I bought it, since once washed, it was about half the weight that it was pre-washing.
I'm quite happy with this. I wouldn't have thought I would be, since it is so lightweight, but it really works well. So on that high, I took my other favourite sweater:
and came up with this:
I'm surprised by this fabric - I wasn't too hot on it at first, but it looks really good. Especially with a brown tank top layer, jeans and my brown suede boots. When I actually start wearing shoes other than flip flops, I'll even get a modeled shot for you. (the pattern does actually line up, it looks wonky here - probably because of the angle of the picture.
Oh, and the best part? Drafting, cutting the pattern, cutting the fabric, and sewing it up? Start to finish, 2 hours for each of them. What's not to love? I still have some more knit fabric - a great dark grey cotton lycra, and another beige and green based print, so I should have a couple more soon. Plus the hand and machine knit cardis I'm working on - looks like my cardigan wardrobe will be set for fall!