If you were looking to replace the guides on your best rod, what type guide/tiptop would you use? There are so many different brands, with so many different inserts that I am very confused. I would want guides that could withstand braid, but I also want the lightest guides I could get. Suggestions? For what it is worth I would want micro guides for a casting rod.

Alconite will work for pretty much everything....

As Chris said, Alconites are a good choice.  Not sure how small you plan to go of what line you're putting through it, but somewhere in the 4 or 5 size for the main running guides would be about right.  If you're not running braid to leader and not fishing in ice cold temps then you might be able to get away with a smaller guide, but the law of diminishing returns doesn't give you a whole more more benefit as you go that small at the cost of a little durability and not being able to use leaders connections later.

 

If you really want to go all out and money is no object, then titanium frames and torzite rings are even lighter.  And you could downsize a half size since the inserts are so thin.  Again, law of diminishing returns comes at a cost.  In this case, $7 a guide.  I've done a few rods in the past when you could get titanium frames SiC guides in the concept series and they are phenomenally light.  But they were specialized rods and needed the weight reduction (a 10'6" ultralight for steelhead for a gentleman who had grip issues for one).