I got mine a few years ago and I did a ton of research. The Brother CS6000i is what I finally settled on. There are machines that are bigger and do a lot more, but for a general purpose machine, you really can't beat the value.
Amazon product ASIN B000JQM1DE
When I grabbed it (in 2013 as Amazon has reminded me), it was about $150. It looks like it's gone up $50 in price, but it's still worth it. You get so many stiches and I haven't had a problem with it in 8 years. Now, it does require maintenance (like all machines), and you basically have to split the machine in half to oil it, but there are youtube videos that show you how.
On a quick look, it seems they have updated this machine some and put a new one out:
Amazon product ASIN B08BH5GTNC
I cannot attest for this one, but it looks like it's getting high marks from a lot of places. Either iteration of this machine is not too expensive, it does button holes, it has every stich you'll need (and some fancy ones too), and it's fairly easy to maintain.