You should integrate some sounds from the classic video game into your stuff.
As for what to say, that comes down to your branding. When I had Mitch Craig make me drops, I had him say my name alone so I could put some swooshes with it. I also had him say these terms:
“D-Jam…bringing you that deep Chicago sound.”
“D-Jam…taking you global.”
I used the first one for deep house mixes and the second for trance and tech house mixes.
I later had Lesley Lyon make me more drops. I wanted a British female voice reminiscent of the announcers I would hear on Radio 1. I had her say these phrases:
“You’re logged in with D-Jam.”
“You’re listening to D-Jam.”
“TheMovement.FM presents D-Jam.”
The first two seem more generic, and the third was more for an online show I take part in. I think good advice if you buy or record someone is to make it so you can chop them up and edit them as you please.
So think about your sound, style, brand image, and then write a script from that.
Have you seen this? http://www.digitaldjtips.com/2012/02/dj-drops-guide/