Well, I play Type 1, 2 but seldom Extended because all those combo-ish decks get to me. The only few Extended decks I can play without bursting my wallet is Sligh or White Weenie.
I do play Type 2 tourney standard decks once a while to get a feel of them and later, disect them for analysis. I play Type 1 because Dark Ritual isn't banned there. Although I don't own the P9 (I don't care for them even), I still have a blast building really nifty Type 1 decks.
I do play casual decks but the problem here is that the casual decks I build are old school Magic decks, meaning that in fact they are meant to be casual, they still have tourney qualities in them.
I don't really play multiplayer because all my decks are meant for duels only. I also play illegal Type 1 decks that feature 4 Strip Mines or 4 Crop Rotations, however, that's just for the fun factor only and not to show off that I have these cards. It's pretty amazing that what a Ponza deck can do in Type 1.....
Well, that enough ranting from me.......