Midfield
Phillip Cocu
One of my personal favourites, Cocu is a proper, typical Dutch total footballer. Strong at both ends of the pitch, he was one of the few Dutch players Barcelona warmed up to during their tough spell in the early 2000's. Even during that tough time, he at least had one La Liga title for Barcelona, scoring 12 goals in that season. For his whole spell there, he was one of the first names on the team sheet, being a regular first 11 player and being ever reliable for Barcelona.
When he started his career, Cocu started off as a left winger before being moved to central midfield whilst maintaining the attacking role, showing great skill and technique as well as a knack of scoring goals. When van Gaal got him for Barcelona, he was used as a box-to-box midfielder, being strong at both the defensive and attacking phases. When van Gaal left the club, Cocu was pushed into more defensive roles by the other head coaches as they wanted to fully utilise his excellent defensive ability, eventually settling into a defensive midfield role and even playing as a central defender in a few instances. Such is the level of talent in Cocu, and it truly demonstrated his completeness. His loyalty to Barcelona during their tough spell is proven by his 291 total appearances for Barcelona, which were the most by any foreigner until a certain Lionel Messi broke that.
Luis Enrique
Let's list the positions he's played in: striker, second striker, attacking midfielder, left winger, right winger, central midfielder, defensive midfielder, and full back. He's played pretty much everywhere and been useful in pretty much every phase of play. A leader on the pitch, Lucho's tenacious, hardworking, and never-say-die attitude has made him a fans' favourite wherever he was.
His standout qualities include his versatility, his skill, and his tireless nature. He would run on and on, non-stop, and he'd keep on fighting until the final whistle is blown. What makes him stand out is the number of crucial and comeback goals that he's scored, particularly for Barcelona. That, combined with his versatility and determined approach to all matches, made him a Barcelona legend.
Uwe Bein
He's not that well-known to many people, but those who know him know that he's one of the best attacking midfielders Germany had in the 1990's. Franz Beckenbauer stated that he had the "killer pass" and that was very true about him. One of the most creative midfielders of the Bundesliga, Bein was also a skilled dribbler and goalscorer. His success includes the 1990 World Cup title in which he was involved in 4 out of 6 matches.
Starting off at Kickers Offenbach in the lower divisions, Bein came up as a hugely talented player, scoring 72 goals in 153 games for them (in his final season, when Kickers were at the Bundesliga, he scored 14 goals in 34 appearances). When he moved to FC Köln, he was deployed in a deeper role, scoring fewer goals, but that only enhanced his passing and playmaking, thus starting the path towards becoming the "deadly passer". Many Bundesliga teams were after him at the time, but Hamburg got him eventually. Initially, he struggled there, with several Hamburg fans questioning whether he could really step to the level of the Bundesliga. Having stated that, the whole team was in transition, and player power was rife there. Bein, being introverted and shy, struggled to settle into the team. However, once Willi Reimann came in and cleaned up the mess, Bein started to show what he was all about, particularly in the second season, when he scored 15 goals in 28 matches. After that second season, though, he moved to Eintracht Frankfurt, where he constantly challenged for the Bundesliga and made players like Jay-Jay Okocha and Tony Yeboah thrive.
For Die Mannschaft, things weren't as rosy. He did play 4 out of 6 matches in the 1990 World Cup, but Möller wasn't happy about the lack of match time. Luckily for him, Bein got injured, and Möller got a look in, culminating in a final where Bein wasn't involved. He didn't participate at all in Euro 92, and when Vogts took over, he rarely got a look into the national team, retiring in 1993 as he frequently got overlooked for his fellow German counterparts. His soft personality may have played a role here, and if he probably had a stronger personality, he might have had a bigger legacy for the German national team, and his reputation wouldn't just be locked into the Bundesliga.
Roberto Donadoni
He was one of the best wingers, if not the best, Italy ever had. He was one of the first players bought in the Berlusconi era, and he certainly was one of Berlusconi's best buys. During his time in AC Milan, he won 6 Serie A's and 3 European Cups. It's scary to think that he almost died during a football match (1989/90 European Cup), and luckily for AC Milan, Italy, and football fans all around the world, the Red Star's physiotherapist was on hand to save his life.
Donadoni was a complete attacker who had it all in his locker. This, combined with his stamina and hardworking nature, made him perfect for Sacchi and Capello in their 4-4-2. He played on both sides and as an attacking midfielder, but he mainly played as a right winger, though under Sacchi, you'd expect him to be involved everywhere. His close control, agility, and feints made him tough to read and contain. His creativity and deliveries from out wide and through the middle created lots of chances for his teammates. His two-footedness made him dangerous cutting inside and going outside, particularly with his long shots, which were always precise. He also always tracked back and supported his teammates defensively, showing tactical awareness and the willingness to work for the team. He really was the perfect player for any football team.
Emerson
No, not the one who played for Middlesbrough. Emerson Ferreira da Rosa was a solid and tenacious yet elegant defensive midfielder who combined his steel and energy with his amazing skill on the ball. When he started off in Brazil, he played a more attacking role, but since he moved to Europe (starting at Bayer Leverkusen), he has played as a defensive midfielder for the rest of his career. That didn't stop him from getting involved in the attacks, though, where he demonstrated precise control and dribbling as well as perfectly-weighted passes that dissected defences. Wherever he went, he always challenged for honours and even won some trophies, and wherever he was, his teams were always strong in midfield and tough to break open.