IMO you should look into a used corolla, 8th or 9th gen (1998-2002, 2002-2008 respectively) they use a tried and true engine the 1zzfe. (avoid 2000-2002 if possible, they burn oil)
I own a 1998 corolla VE, thats the low end with a 3 speed auto transmission... no overdrive. I've recently acquired a scanguage II and with careful monitoring ive been able to get ~40 mpgs(its rated at 26) (I havent updated my fuel log since getting the SGII, no fillup yet!)
the 2009 corolla is the 10th generation and it uses a brand new family of engines and transmissions. If you can find one look for a 2006-2008 LE
