Several professional logo design services are known for delivering top-notch logo designs. The choice depends on your specific requirements and budget. Here are some well-regarded professional logo design services:

1. **99designs**: 99designs is a popular platform that connects businesses with professional designers. You can start a design contest and receive multiple logo concepts to choose from.

2. **Crowdspring**: Crowdspring is a design crowdsourcing platform where you can launch design projects, including logo design, and receive proposals from a community of designers.

3. **Designhill**: Designhill offers a variety of design services, including logo design. You can create a design contest or work directly with a designer.

4. **Looka (formerly Logojoy)**: Looka (formerly Logojoy) uses AI to help you generate logo concepts and then customize them based on your preferences.

5. **Hatchful by Shopify**: Hatchful is Shopify’s logo maker that provides customizable logo templates, and it’s a simple and cost-effective solution for small businesses.

6. **Tailor Brands**: Tailor Brands offers logo design services powered by AI. You can input your brand information, and it will generate logo concepts for you to customize.

7. **Penji**: Penji is a design service that offers unlimited graphic design, including logo design, for a monthly fee. It’s suitable for businesses with ongoing design needs.

8. **Looka (formerly LogoMakr)**: Looka (formerly LogoMakr) is an online logo maker that allows you to create your logo with easy customization options.

Each of these services has its own strengths and pricing models. When choosing a professional logo design service, consider your budget, design preferences, and the level of customization you require. Review portfolios and client reviews to ensure they align with your project’s needs and goals.