Overweight is a person with abnormal weight. Obese is an ill person, suffering from extreme weight. Chubby and pudgy may serve as compliments I think. Fat is an insult.

Here's some advice: search each word online, not for a dictionary definition, but to see how these words are used in articles and blogs. You'll get a feel for the subtle differences between them. As a short answer, blob and fat are unkind descriptions, but "fat" is the most common word out of the entire list. Chubby and pudgy are not as blunt, but still unkind descriptions of someone. Overweight and obese are more descriptive, so you'll find these in articles on medicine and health. "Overweight" is the kinder preference to using "fat" in a sentence. Replete is the only positive word in the list, it means you're full and well-fed. And you show it.