I've tried a variety of AI tools, but I find ChatGPT and TensorFlow to be the most versatile. ChatGPT is excellent for generating ideas and answering complex questions quickly, while TensorFlow provides powerful libraries for building deep learning models. For someone new to AI, I'd recommend starting with simpler tools like Google's AutoML, which automates a lot of the heavy lifting, making it easier for beginners to get results without extensive coding knowledge.

When it comes to building AI applications, I've found PyTorch to be really user-friendly, especially for prototyping. Its dynamic computation graph is ideal for experimenting, and the community support is fantastic. Another tool I frequently use is OpenCV, especially for computer vision projects. Combined with libraries like Scikit-Learn for data processing, these tools allow for seamless model building from start to finish.

One AI tool that stands out is Hugging Face. They have a range of pre-trained transformers that are ideal for natural language processing tasks. Their libraries are open-source and come with extensive documentation, which is incredibly helpful for both beginners and experts. For deep learning, I find Keras with TensorFlow backend to be intuitive and efficient, especially when developing and training models quickly.