replicant2020
One criticism I hear quite a lot is that DFW's own writing on the topics of addiction and depression are shallow and not representative, though I can't really say how true this is for lack of experience.
The thing that worked for me in I.J. was that Wallace managed to combine elements of comedy and tragedy, not just in alternating parts but often within the same body of text. Some chapters are so tragic as to be darkly comic, in particular some of the descriptions on the backgrounds of members of AA.
Plus, don't forget that Infinite Jest isn't his only work :). I haven't read The Pale King but have heard that it does away with a lot of the verbosity of I.J. and feels a lot more focused, and there are other works of fiction and also his more journalistic essay-ish type pieces, for example those from A Supposedly Fun Thing I'll Never Do Again (the collection, though the titular piece in particular I found very funny).
I'd also highly recommend Oblivion: Stories, even if Infinite Jest didn't gel with you, as I think it's as emotionally powerful but a lot more focused than Infinite Jest. It doesn't attempt the comedy/tragedy mix that I.J. seems to try for, and as a result the stories are shorter but just as affective.
Oh what a terrible person, to have not read everything in an arbitrary list of authors and books that I feel like name dropping.