Hey all:
This forum is meant for people to share who they think are up and coming prospects in their youth squads. If you have knowledge about your teams reserves please give us a heads up so we know who to look out for.  I'll start.

Arsenal: 
Benik Afobe (CF) - tall, fast, and scores for fun; was going to break-into the 1st team this year before he had a season-long injury; probably our most exciting next prospect.
Nicholas Yennaris (RB) - another 19 yo who looks bright; he came on for 1 match this season and acquitted himself very well
Oguzhan Ozyakup (MF) - this young dutchman is technically gifted and a good passer of the ball; I saw a few reserve games with him and he bossed the field; one to keep an eye on
Kyle Bartley (CB) - tall & strong; I haven't seen him myself but there's a lot of buzz about him so I included him; he's on loan to Rangers
Henri Lansbury (MF) - scored at WHL on his 1st team debut and now on loan to West Ham; you probably know him from the under-21 NT; I really like this kid b/c he's full of energy & grit but he also has a great shot; I really hope we hold onto him and give him a proper chance b/c he's good enough to attract offers now.

Dude, can you describe Chuck Aneke? based on the videos i watched, he can score and kinda deadly up front! plus he can dribble and play as a target man.. correct me if i'm wrong.. to me he's a good prospect for the club..

Barcelona:
Tello (forward/winger)- a 20 years old striker who is showing that he can play easily in a big club like Barcelona. Aldredy did a lot of goals in the spanish competitions and Champions league.
Thiago Alcantara (Midfielder)-  if there's a player who can remplace Xavi or Iniesta that's Thiago.
Rafinha Alcantara (Atacking midfielder/false 9)- 19 years old player. He's Thiago's brother and he's promising even more than his brother.

... (They are the most promising players of Barcelona but if you want to see more talented players than look at Barcelona's B team )

R. Madrid:
Varane (defender)-  a 19 year old player. He surprise me every match he play. I think he will become a world class defender. (in my opinion he's much better than Pepe)

Athletic Bilbao:
Muniain (Winger / Forward)- a 19 year old player. Well I think much of us alredy know him.

Malaga:
Isco (Attacking midfielder)- a 19 year old player. He's the pearl of the team. It's young but he's alredy a good play maker.

@Footaholic I'm really excited about Afobe! I've seen his videos and I can say he's quite a talent. Bartley is doing pretty well as far as I know. Ignasi Miquel is a better defender than Squillaci for sure! Sell Squillaci off and promote Miquel to the first team! Another guy of ours to watch out for is Wellington Silva.

@Vantheman Aneke is definitely a guy to watch out for! 18 yrs old and is on loan to Preston atm.

@Nico Tello is quite a talent! Impressive goal scorer too. Thiago is a star in the making. Muniain...man he single-handedly terrorized Manchester United! I won't be surprised if he moves somewhere big (not Real Madrid I hope...)

@VantheMan: I'm aware of Aneke and there are many others I left out. The ones I listed caught my eye the most & I tried to avoid mentioning names that non-Arsenal fans might already be familiar with (e.g. notice I  left out Miyaichi, Campbell, Henderson, etc.)

@nico: thanks for participating. I know Barca is tuff b/c probably their whole B squad is talented but which ones stand out to most to you?

Barcelona B/Youth squad has a lot to offer Rafinha Younger brother of Thiago Alcantara they say he is much better than his older brother, Gerard Deulofeu "The next Messi" , Martin Montoya attacking fullback his game is like Dani Alvez, Muniesa and Bartra our future Center backs, Cristian Tello you know who is this guy scored a brace in his UEFA-CL DEBUT, Issac Cuenca good dribbler, good crosser, Sergi Roberto ....

@Footaholic
The most talented players of Barcelona B team for me are:
RDF - Montoya- 20 years old
DF - Marc Bartra - 21 years old
FW- Gerard Deulofeu - 18 years old
MF - Rafinha - 19 years old
MF- Jonathan dos Santos Ramírez -21 years old 

I've seen plenty of youth players that looks to have a great future ahead of them. I'm more concentrated in the very young players because that's where talented is born, and there is one player whom I believe will have an excellent future ahead of him (circled in green).
This photo was shot during VDS Dream Team testimonial match, and there was an UNDER 13 match between Man Utd and Ajax, and we all know that Ajax is has one of the world's finest youth academy. 

Anyway, the kid's name is Zharookie (or something like that), and I believe he's going to be the next Puyol. Definitely someone to watch in the near future

Oh I would like to see these little reserves to be the football's next stars.

@hesiinburg: good man... studying talent that young. I'll try to remember his name (not easy to forget).

Luc Castaignos he is 19 years old and he plays at Inter. He made his first goal at his tribute for the nerazurri's. But i dont know why Ranieri did left him on the bench. He is a youth that can create something for Internazionale.

I agree with Nico10 and here are some more
Isaac Cuenca (FC Barcelona) - Very talented winger and has been playing alongside Messi and Alexis for some time now. He recently got promoted, though.
Sergi Roberto (FC Barcelona) - Plays as an attacking midfielder. Also talented. Plays similarly to Iniesta.
Andreu Fontas (FC Barcelona) - Defender.

And @Nico10, Varane is better than Pepe because Varane is very calm, talented, and tall. He plays fair and has an incredible sense of position. The only reason he doesn't play regularly is because Pepe has been at Madrid for a long time, Pepe gets paid much more and they have to get something in return for all that money, and Pepe is more experienced (in fouling).

boyata - man city .

Ricky Alvarez,Andrea Poli,Guarin,Coutinho(Inter) Mauricio Isla(Udinese),Gaston Ramirez(Bologna),Borini(Roma),EL PHAROU(EL SHARAWI)AC MILAN,Bonnucci,Giacherrini(Juve)

Phillipe Coutinho is this year loaned to Espanyol he will return to Inter in the summer.