1. Murray, Nadal and Djokovic are all defensive baseliners. They pretty much personify the grinding style of 00s. Each has a monster stamina, low UE count, good serve return. Yes, they all do hit winners at times, but only because they are top 4 after all, not entirely one-dimensional. Djokovic is perhaps more offensive than Ferrer, but he is still a defensive player. Monfils and Simon are also in this group.
2. Offensive baseliners are guys like Berdych, Del Potro, Soderling. They are tall and strong - they need to hit winners from far away. They prefer to keep the points short, as they do not move very well. Isner and Raonic are in this group too, despite their huge serves - they actually do rally and have decent forehands.
3. Dimitrov, Dolgopolov, Federer are all-court players - some gravitate to the baseline more (Wawrinka), some rush the net more (Federer). This group has good slices, volleys, overheads, dropshots - they need to mix their shots up to compensate for the lack of stamina or power.
4. Llodra and Stakhovsky are S&V players. Federer was a S&V player before 2002.