Lucas hands down. better all round player and also has a better attitude.
By all round player, I mean he can attack as well as defend, he likes to get forward, and although we only see glimpses of this, such as Benfica, Chelsea and more recently Blackburn, when given a license to get forward, he can comfortably. He does try to pick a pass, or an assist, some may not come off, but at least he tries to get attack's rolling. If you look at the Chalkboard (linked later) you will see Lucas rarely gives the ball away, averaging around 2 misplaced passes per game, one of the lowest in the squad. As opposed to Poulsen, who is more at home playing the ball back to the defenders or to the second midfielder in basically the same position at him, he is more comfortable keeping position and being boring really than trying to go get a goal.
Even in defense, I would rate Lucas higher. For those who say Lucas gives away too many stupid fouls, or fouls in dangerous positions, have a look at the Guardian Chalkboard(
http://www.guardian.co.uk/football/chalkboards/create ). Over the last few games, I can only see 1 foul in any location that could be deemed dangerous, I might just add here that he has won many more free kicks than he has conceded. Poulsen is not the quickest and to be honest in the few months he has been here so far, I actually cannot recall a single important challenge that Poulsen has made to benefit the team.
In terms of attitude, well Lucas's is well documented. Never spoke out against the fans who booed him at games ( which was very disrespectful I fell ), just kept working hard in training and on the pitch , strived to make those fans like him, or even better, respect him for the effort he puts in for the team week in, week out. When he scored a few weeks back, he did't celebrate in an act against the fans to prove a point, no, he celebrated with pure joy for the club he wants to play for. Poulsen has been quite to be fair since he joined the club.The one main comment I remember from him is something about his hair and his image and he wouldn't change it for Liverpool. ( Lucas did!
)
Also, for those saying Shelvey, it's a bit premature yet and a bit slightly off-topic! But Lucas for me is the better player..