I have seen a ton of carpet tiles used in the past. Most are commercial in style which can be fine.
The residential styles that are now emerging are really cool too.
I think the seams are almost invisible on the Milliken carpet tile line called Tesserae. It is a very good looking carpet and it has a padding attached with a very subtle self adhesive on the bottom.
For a DIY installation this is a great application. The only downside no way to do stairs with this. I suspect Milliken offers carpet in the same colorways that a professional could install for you, but if you are just doing some rooms, basements or whatever, this can be a great application!
Check it out: MILLIKEN CARPET TILE