Which bike is the more lasting ?

r15,karizma,apache,pulsar,cbz,hunk or fazer...i'm giving more priority to longevity because my bro's p180 has major problems with it...it is about 8 years old..it is giving mileage only about 13 km/l...it has problems with transmission..and the bike starts to vibrate just when it reaches the 5ht gear(even when the accelerator is not given)..we gave it to bajaj for repairs but saw improvements only in the transmission..the mileage got even worse...so it's almost unusable now