Although I really liked the first three seasons, I think adding Lois in season 4 added a spark the show was missing, an element of fun. Lois brings out the fun side of Clark and allows Tom to do a bit of comedy which he is very good at and Tom and Erica have great chemistry.

I like Chloe but I do think she has been used more as plot device than an actual character this last season and I have *ahem* problems with a certain theory people believe about her.