Tom and jerry is my second favorite series of all times(the classic one).
Looney Tunes is also good. I watched the 2011 series and it was very good. I watched around 50-60 episode of the old Looney Tunes and it was pretty nice.
Tom and Jerry wins for me.
Looney Tunes has more classic characters and episodes that I can laugh at.
Tom & Jerry are great and very laughable but I don't think they quite measure up with what Looney Tunes has to offer and creativity.
For Looney Tunes I mostly just like the classics, Duck Dodgers and The Looney Tunes Show. I haven't seen Tweety and Sylvester Mysteries and only seen clips of Tiny Toons. I hate Baby Looney Tunes, Loonatics Unleashed and Wabbit/New Looney Tunes.
For Tom and Jerry the only spin-off incarnations which I hate is Tom and Jerry Kids and those DTVs where they insert Tom and Jerry into random classic movies.