For years I much preferred handheld gaming, but now it's mostly console. I love playing Super Mario 3, Super Mario World, or other great platformers on the 3DS or GBA SP, but then I started to really want to play those games on a big tv, where you can really appreciate the bright, colourful graphics, etc.
Plus, I like playing big adventure games (Uncharted, Ratchet and Clank, etc), and I find these games are much better suited for a big screen.
Also, I have kids now, so console gaming is much better for us to play together on the couch.
I also find I don't have the attention span when playing on a portable. If I'm playing a portable in the living room on the couch with my wife beside me and the tv on, I will tend not to play as long. Whereas, if I go to the basement, I will get more immersed in the game and play for a couple of hours. That is the downside of consoles for me though, I'm regulated to the basement.