i have a Nike Imara, $99. does all the simple things i need to see.

-current HR (bpm or % max)
-timer
-data (after you stop the timer. shows time, calories burned, avg HR)

if you're looking for general fitness (vs. training for racing) then a general max HR could be used. since you probably won't need to have HR specific intervals that dance the line between aerobic and anaerobic that you would need to know exactly then you can calculate your max (220 - <AGE>) and use those zones. if you're trying to lose weight you'll probably be very familiar with zone 2.