If it's careful, reasoned discussion of the issues surrounding the EU referendum (rather than hyperbolic rhetoric and scaremongering) that you're after, then the LSE's BrexitVote blog is a very good place to start.
A case in point: Nicholas Barr, Professor of Public Economics at LSE's European Institute, has set out his reasons why, on balance, he'll be voting Remain. His article considers economics, trade, political status and sovereignty, addressing the claims of the Leave camp and the uncertainties an EU exit would involve as well as listing (albeit perhaps a bit briefly) the actual advantages of staying in Europe. His conclusion is that the EU is fundamentally a valuable institution and that if it's judged to be broken, then it's best to work from within to fix it rather than to chuck the whole thing out.
For anyone like me who generally buys those arguments and also recoils from the Leave campaign on account of the various crackpots endorsing it, however, Lee Jones' post gives serious pause for thought. Jones, a Senior Lecturer at Queen Mary University of London, puts the leftist case for Brexit - one that is common in continental Europe but that has rarely been heard during the debate here in the UK because of Jeremy Corbyn's support (albeit half-hearted) for the Remain campaign, with the consequence that Brexiters have come to be seen almost exclusively as xenophobic Daily Mail-reading Little Englanders on the right of the political spectrum.
Jones essentially takes the opposite view to Barr: the EU isn't fundamentally a Good Thing, locks in protection of the neoliberal interests of political and economic elites and locks out accountability and democracy (TTIP being a case in point). His argument is that no amount of reforms brought about by working from within the system will bring about change and that the Left would be better having the courage of its convictions, pushing for a Brexit vote and a return to governance at the national scale, and believing in its ability to triumph over the Little Englanders and win over the electorate.
Thought-provoking stuff for a confirmed leftie, and - to my surprise - I'm finding myself slightly conflicted with only a couple of weeks to go.
(Thanks to Simon for the first link.)