Side Street Inn    Colin Nishida's unassuming bar, where the regulars knock back icy beers while watching sports on TV (or singing karaoke), has some of the best down-home food in the Islands. Most dishes are served heaping, family style. The fried rice and pork chops are a must, but you can't complain about the katsu, the spinach salad or the Portuguesestyle clams. Great for kicking back (except for the people lined up and eyeing your table, in even greater numbers now that Side Street has been featured on TV food show "No Reservations"). By day it's a lunch counter.  1225 Hopaka St. 591-0253. 2 p.m.- 2 a.m. daily. Reservations recommended for large parties. AX, MC, VS. No checks. $-$$.