X-Men (2nd series)
Title changed names several times during its run. Originally begun as just "X-Men" (the 2nd series of that name), it changed to "New X-Men" with #114 (becoming the first series of that name). Title reverted back to simply "X-Men" with #157 and later changed with #208 to "X-Men Legacy" (the first series of that name) and remained with that name until its final issue, #275.
#1-113 - X-Men (2nd series)
#114-156 - New X-Men (1st series)
#157-207 - X-Men (2nd series)
#208-275 - X-Men Legacy (1st series)