I had a lecturer who said "gooey" and it bugged the hell out of me.I can't stand it either. I always say it and read it as, "GUI".
I say "gooey" which is the right way to say it=P
Of course, my friend says "gwai" like "mogwai" which just sounds odd to me. It was two to one against last semester so "gooey" won the day;-)
Ah the internet. I could start a whole topic on how we say all these acronyms of ours. There are some I simply avoid speaking in real life because i'm sure i'm getting it all wrong as usual. Such as (and smoothly stepping closer to the original topic) MMORPG, which can either come out as "em-em-oh-arr-pee-gee" or "mi-mor-peg" for me..