Where is the best place to order quality t-shirts for employees?

There is no one-size-fits-all solution to such a generic question.

You need to take things into consideration like what country you are in, what type of physical heath most of your employees are in (fatter people won't like the same shirts as thinner people, so you generally want to play to your crowd), the amount of female to male employees can play a factor, what type of logo and design you are going for is important if you want it to look good because deciding if you're going with screen printing or silk screening is also a huge factor.

There are typically a few major generic t-shirt brands available as a base. Start by picking your favorite that also matches your employee demographic best.

Next you need to decide on your design and what style of printing you are going to do.

At this point pretty much anyone can finish the job. Most people just go with a local company because it's easier to do business, testing, shipping, returns, deal with problems, etc with a local company than trying to interact with some random giant company somewhere in another country.

It's going to depend what country you're in. But for the most part, you're just printing/embroidering your logo on an existing product. The quality of blanks ranges greatly. In the UK if you look at somewhere like https://www.buytshirtsonline.co.uk you can order a whole range of blanks for not much and figure out what cut/material you like. My personal favourite is a heavyweight, boxy Gildan. But that's not for everyone!

Not the most premium but Bella Canvas or Next Level "Heavyweight" Tees, usually sold as blanks and can be used for company branded apparel. I would recommend the Heather ones which have a poly blend, soft and durable.

Their normal weight ones are also ok but might not feel as premium.

Jiffyshirts.com is one place where you can place bulk orders.

Our company uses teesprings triblend option, which come on the bella canvas blanks noted by another user. They're comfy and they don't wrinkle easily. Good enough screen printing that they last as long as t shirts from the store.

There are several brand name companies that will do that. I have a couple of company-branded Patagonia and Lululemon t-shirts that are in great shape after almost 8 years.

The highest quality t-shirts I've purchased have been L. L. Bean Unshrinkable Tees. They're not cheap but they last close to a decade.

Los Angeles Apparel. They’re the successor to American Apparel, and make very high-quality, American-made t-shirts.

The American Apparel tee variant on Printful is pretty good