import re
text = "\r\n1115492_23181_0_0.g.vcf.gz.tbi\r\n1115492_23181_0_0.vcf.gz\r\n1115492_23181_0_0.vcf.gz.tbi\r\n..."
m = re.search(r"(?m)^((?:(?!\.g).)*\.vcf\.gz)\r?$", text, re.M)
if m:
	print(m.group(1))