since my pnp days many years ago i have always favored elven fighter/thieves. while halflings do get better saves, i try not to build my character out of stats but rather the other way around.
mentioned already was the ease of gaining tons of items and cash through picking pockets and robbing merchants. in a real game the blatant excessiveness of this wouldn't exist, as no DM is as stupid as the merchants in this game. also, you don't really need the cash or the items. most of the stuff a thief will want to use is either found or a gift. for this game i really haven't found anywhere i absolutely had to use pick pockets, and as it really doesn't fit in with the way i play my character, that stat stayed minimum.
i primarily concentrate on stealth and traps. if there's a lock that needs opening i can either bash it open or use a knock spell. with the boots of speed and high stealth i can scout out an entire area and then plan my route accordingly.
the nice thing about having the main character able to use shadows is many of the interactions can take place while you're hidden, then the bad guys turn red but can't see you, allowing you to neutralize their "surprise" advantage rather than having all of them blast the few members that were visible simply bacause your party was strung out due to bad pathfinding.
my favorite character brought in from bg1
STR 19 (was 18/58 but used the tome)
DEX 20 (was 19, tome, blah blah blah)
CON 9 (it's an elf
, besides i get to choose my fights very easily)
INT 11
WIS 8 (believe me, i play this semi-low stat with perverted glee
)
CHA 19 (was 18, very nice with helm of glory, nymph cloak, and blade of roses for a melt their panties 23; i figure this will come in handy when he retires from adventuring to become a politician, or perhaps emporer...)