I recently began doing some freelance programming and making a few small games for the iOS and have gotten a bit of money from it all. I am now planning to move from blender to a more professional tool for modeling. I want to use either 3DS Max or Maya. Personally I've more experience with 3DS Max from school but really I would have to learn both to a degree so which do you think is better? Alternatively, do you think I should use something else? Or am I just over thinking this and should go with personal preference (in my case, 3DS Max)? I don't really like Blender very much and I've used a few other software like Milkshape but I've always really liked 3DS Max.

Some companies are all Max, some are all Maya... some are even all Softimage...
There's big name companies on each side of the fence.

The previous company I worked for used a mixture of Max/Maya/XSI (based on people's personal preferences).

If you really like Max then just use Max. Sure, there are minor differences in the features between Max, Maya, and XSI, but they are just that - minor. Use what you're going to be the most productive in, based on how you work and what you know.

Thanks you guys, I purchased 3ds Max today and started getting used to it again, it really wasn't that hard and I started working on some art for my next game.