Favorite Brand of Sewing Machine Thread?

Different machines sometimes have preferences - not helpful, I know.

I've been happy with Coates & Clark, Gutermann, and also the HL knockoff of Gutermann. I would stay away from generic brands

Thread is one area I never skimp on. Buy the best because it's a main component of your finished product. For garments I have always used Gutermann or Mettler. For quilting or all cotton threads I use mostly Aurifil. However, other brands are coming out with some great threads (regular and specialty).  I like and have used these:

Scanfil Thread - Netherlands company that makes Organic Pima cotton fiber thread.  Gorgeous thread and colors.

Wonderfil Specialty Threads - Great specialty thread options (glow in the dark, metallics, iron-n-fuse, rinse-n-gone).  They also sell a wide range of prefilled bobbins.  

Superior Threads - They have really stepped up their game and have a wide variety of types of thread.  Quality is excellent.  

My Janome likes Aurifil thread but she also tolerates the Hobby Lobby $.99 stuff, too.

I agree with all of this. I'll use Aurifil Wonderfil when quilting, especially if I am making something that needs matching corners/seams. The 80 weight thread is just as strong as all purpose thread and is so much thinner. Seams iron open completely flat with the finer thread. They sell a pack of 40 pre-wound bobbins in a multitude of colors that's a great way to get a large sampling of colors if you don't need a lot. Also, there's an advent calendar of threads coming out at Christmas.  The shop that I used to buy from in the UK is selling it for preorder for 78£, so check your local shops.  That's tempting, as it's less than 5£ for a (presumably smaller) spool. 
ETA: OMG! It's $145-150 to preorder this in the States! Why ever could that be? Hopefully that price will come down with the reduction in tariffs.

I use Gutermann and Mettler when I need a larger color selection for a good color match, such as when I'm topstitching. I even use Coats & Clark, even though the shop where I bought my machine said that I should never use it.  It's fine! But how the heck are we going to match thread now without being able to see it in person???

Superior Threads makes a water dissolvable thread that's great for basting. But be sure to keep it in an airtight bag or container or humidity will dissolve it first!

Congratulations on your new machine!

I’m pretty sure most of the regular sewing thread I have is Coats & Clark and I really haven’t noticed any issues related to the thread being bad or low quality. 🤷🏻‍♀️ I use Sulky, Madeira or Brothread for my embroidery machine.

I use Mettler or Aurafil. Both are great.

Aurifil

Which of the Superior threads would you use to top stitch? I feel like the 80wt Aurifil Decobob that I have is just too fine for most things. I don’t mean a heavy duty thread, just one that’s thicker than the Decobob. I need to do some research!

ETA: I went digging around on Aurifill’s website. They have a lot of threads! I feel like I’ve just seen Decobob in quilt shops or specialty threads. There’s a lot to explore!

Do you mean the Wonderfil Decobob thread?   80 wt is definitely too fine for topstitching that you want to be seen.  You'll want to go with a small number weight.  Depending on the thread it will be a 30 or 28 wt.   Gutermann sells a 30 wt poly topstitch thread.  Aurifil sells a 28 wt.  Just remember when you go thicker on thread to go with a larger needle - either a 90 or 100.   Then you would use regular thread in the bobbin.