Since the 2005 Nadal will never come back, I figured I would put this in the Former Pro Player section.
Nadal was of course a much less complete player back then, but he still dominated clay in a manner never seen before. He had convincing wins over JCF and Coria, two of the best clay courters of the time and beat Federer soundly in the FO semis, perhaps even more soundly than in the 06-07 FO finals.
The 2005 Nadal was exciting because he was still an up and coming, inexprienced teenager with lots to prove in the ATP tour. The 2006-2009 Nadals relied on a winning formula which little was able to break, making Nadal's game boring to say the least.
Back in 2005, he was arguably the fastest player back then when his knees were fresh, making impossible gets here and there--his 2005 FO final against Puerta was perhaps the most one sided offense vs defense affair ever but he still managed to pull off the win wtih his amazing defensive ability. His serve and backhand was noticeably weaker, but this meant that the gap between him and his opponents in rallies were closer and he often had to run down more shots, resulting in more spectacular points. His weaknesses also made his forehand stand out as a major weapon. It was heavy, powerful and intimidating and went less to the reverse finishes. He took more risks off that wing even on clay and often hit spectecular DTL and inside out winners which left his opponents dumbfoundered. In the past, I often enjoyed watching the ball grinding painfully with spin in the air off Nadal's inside out forehand to his righty opponent's forehand corner. That thing was just hella heavy. He was more willing to hit drop shots in the middle of a point, as seen in his game vs Puerta.
To me it is sad that the 2005 Nadal will never come back. He was such an exciting teenager back then with arguably the best claycourt forehand of all time and best movement on clay of all time.
Crazy defense and good dropshots against Puerta
Heavy forehands against Coria