What are the best Bitcoin alternatives?

In the ever-evolving landscape of cryptocurrency, Bitcoin often stands as the gold standard. However, for those seeking diversification or alternatives with specific advantages, a range of options exist. Could you elaborate on some of the best Bitcoin alternatives currently available? Which cryptocurrencies offer faster transaction speeds? Are there any that prioritize scalability or privacy? What about those with lower transaction fees or unique features that set them apart from the rest? Your insights on these Bitcoin alternatives and their respective strengths would be greatly appreciated.