I played the three games and more than once too as different characters. You can import your characater from ME2 to ME3. Is is good to make sure you have got the best ending of ME2 into ME3 because what happens to your friends depends on that. Alternatively you can tweak the stats, unless you are very reluctant to cheat a bit, with This Editor
, with it once you start ME3 and save as soon as you are allowed, you can open the saved game with the Editor. Once the saved game is opened you can tweak it changing things that happened to your character in previous games, particularly ME2. If done properly this gives the best start for ME3.
If you didn't get a very good ending in ME2 (every member is alive an loyal) and are playing as a soldier or infiltrator I should be able to pass you a good start for ME3 in case you don't want to tweak it yourself or if you have problems with the editor I can tweak it for you if you send me a very early saved game for ME3.
I may have a good start for adept too.
Smiley456, thanks for the happy ending, I got the best ending but not happy, I will use the mod to have a deserved ending.