Try Super Street. They are not as serious as SCC and they focus alot on women (which isn't bad). They don't take themselves very seriously either so for a lighthearted read and tons of photos check them out.
I geuss it depends on what you're into or what you're looking for. Sure, "Super Street" is a cool mag, but like crash said, they don't take themselves very seriously. Granted they put out a HUGE mag that's up there with SCC, but they don't focus on one thing. one month it's GIRLS *cars* GIRLS, the next a special on Hyundia's. Give me a break. It's a cool mag if you're looking for pics, though.
My personal prefrence is "Honda Tuning". Now here's a mag that's sticks to it's roots. They recently did an article on the everyday teg. Sure the mag is about half the size of "Super Street", but the articles are quality. My first choice is, of course, SCC - shich you already have. Honda Tuning is where it's at.
I don't like any other of the magazines though. Technical insight my ass...
I don't give a whole lot of them credit for obvious reasons. ImportTuner is a shining example. Look at page 92 of the June 2002 mag. These guys can't tune for sh*t. They ended up with less torque than what they started out with. Their VTEC point blows ass.
God have mercy on the soul of the person that pays money for their technical insight.
I got a all those magazines stacked a metre high but their all useless. Reading articles here on TI, i've learned much more than any magazine. Them magazines are often biased and lean more towards advertisement.
Either way you go consider that that SCC, Turbo, Import Tuner!, etc are all owned by the same publishing company. So if you know of a bias that one of these publications may have towards a certain product, vehicle, or style of tuning, etc.. it is likely that some of the others, if not all of the others have that same mindset. Just something to keep in mind. SCC is my favorite. If Honda Tuning was larger it'd be my favorite over SCC. I've never liked Turbo..
Import Tuner! and HCI(sp?) in my opinion aren't worth your time of purchasing, or reading.