Internet speed slow, need a modem/ router upgrade so what do you suggest?

My speeds are terrible. I need to upgrade and was looking for advise for an all in one cable modem/ router combo with wi fi. I currenty have the ARRIS TG862G and need something a lot better. Let me know what you have and if you like it. I am open to suggestions on brand. Also, what would you say is the best out there right now? Any help would be appreciated!!