consider join the 1AT SG coalition.. basically your AT will determine which SG you join but there is a big coalition between them so there is nearly always somone around.
SGs that make up the coalition are:
SNHS - defenders
Precision Rangers - blasters
Armoured Core - tanks
Team G.B.H - scrappers
Union Overlords - Controllers
then there are a few more sgs in the coalition aswell, dark wings, scrapocalypse!11!1!! etc etc 
if you would like to know more reply with your char AT details and we'll point u in the right direction
Thanks for the info.
I got a tanker, a defender and a controller.
well if u interested in joinin the relevant sg's for your AT then the contact people are:
SNHS - all defenders - myself (Tufty), Electrify or Rocket Girl
Armoured Core - Tanks - Pyrius or Mr Knockout (maybe Mr., if u r online with ur tank and want to join but cant get hold of anyone try finding my tank Granite Yak, and i'll confirm their names and if they r on or not ), there are a few more captains aswell.
Union Overlords - controllers - Okton, Inspector Frost, Illusion Gem or Gaea's Herald
contact either one of them in game with ur relevent AT character and i'm sure they'd be happy to invite.
Could someone recommend me a decent SG?
I get so bored when I join the game and waste half an hour trying to find a team. Thus, I wonder if there is any SG I might be able to join to. I play almost every day for atleast couple of hours at the time. I'm quite easy going guy with relaxed attitude. The SG should be somewhat similar.
I play three different characters. They are all around level 35.