I had a nice big thread wrote out but something went wrong and it all disapeared 
Anyway, my top 5 (in no order):
Tevez - Scored plenty of goals, fits in with everyone else perfectly. We'll definately buy him permanently.
Torres - Goals, strength, pace, adapted to PL perfectly. Liverpool's new most important player.
Santa Cruz - Probably the best value for money signing this season.
Anderson - No goals yet, but he's been outstanding and made Scholes absence go unnoticed. Not had many (only City I can think of) bad performances with him in the team. Star in the making.
Sagna - Great at going forward and defending. Big fan of fullbacks who make the Neville-esque overlapping runs and Sagna fits into this category.
Worst 5 (in no order):
Nugent - Absolutely rubbish! So bad he's gone out on loan back to the championship. Thought he might be able to handle the PL but he's got a long way to go yet.
Vorinin - Ignoring the fact that he was free, he's been absolutely woeful. Saw him smack a quality goal in in pre-season and thought Liverpool might have sourced a bargain, but as it turns out, they havn't
Barton - Yet again nothing but trouble. His performances have been dire too. Really rated him at City but he's gone backwards.
Koumas - Ran the show for West Brom at times, looks a different player at Wigan though.
Malouda - This one might be a bit harsh as he obviously has talent. At the start of the season he looked like he might be a permanent fixture in the Chelsea team but I can't say I've been impressed with him since.
Notable mention for Hargreaves too. Only left him off the list because he's been important for us in the big games. My lists concentrate on PL players but feel free to name any from other leagues.

Anyway, my top 5 (in no order):
Tevez - Scored plenty of goals, fits in with everyone else perfectly. We'll definately buy him permanently.
Torres - Goals, strength, pace, adapted to PL perfectly. Liverpool's new most important player.
Santa Cruz - Probably the best value for money signing this season.
Anderson - No goals yet, but he's been outstanding and made Scholes absence go unnoticed. Not had many (only City I can think of) bad performances with him in the team. Star in the making.
Sagna - Great at going forward and defending. Big fan of fullbacks who make the Neville-esque overlapping runs and Sagna fits into this category.
Worst 5 (in no order):
Nugent - Absolutely rubbish! So bad he's gone out on loan back to the championship. Thought he might be able to handle the PL but he's got a long way to go yet.
Vorinin - Ignoring the fact that he was free, he's been absolutely woeful. Saw him smack a quality goal in in pre-season and thought Liverpool might have sourced a bargain, but as it turns out, they havn't

Barton - Yet again nothing but trouble. His performances have been dire too. Really rated him at City but he's gone backwards.
Koumas - Ran the show for West Brom at times, looks a different player at Wigan though.
Malouda - This one might be a bit harsh as he obviously has talent. At the start of the season he looked like he might be a permanent fixture in the Chelsea team but I can't say I've been impressed with him since.
Notable mention for Hargreaves too. Only left him off the list because he's been important for us in the big games. My lists concentrate on PL players but feel free to name any from other leagues.