I've compiled a list of top Chelsea boot designer options. Check it out and let me know what others should be added and your experiences with them. (list isn't in any particular order)
Balenciaga - can be dressed up formally and casually, but not the best option for streetwear. The fit is slightly oversized (half a size big), while the quality is one of the best I've seen.
Saint Laurent (SLP) - styled similarly to Balenciaga, but with a narrow toe. These boots also fit more true to size from my experience.
Common Projects - Great quality and great price point in comparison to the former two. Best buy in my opinion with a variety of options to allow these to worn in any setting. Sizing is true to size to slightly large.
Represent Clothing - Best quality and variety under $300. There is no lack of attention to detail and their Chelsea's share the same quality as the higher price options. Sizing runs large as with most others.
Foundation Footwear - Great quality for the price (one of the cheaper designer options out there with pricing under $200). These are definitely on the more casual side, but have new styles dropping every season. The Rosas style aren't as "sturdy" as the former options.
N.D.G. Studios - Color variety is most similar to Common Projects with a lower price point. Pricing bordering $300, these can be worn versatile as well.
Let me know about other notable brands out there!
Bottega Veneta - for fit and personal experience see comments below
Barney's New York House Brand - seems to be a popular option. See comments for fit and experience.