Like the answer is to all broad vba questions, "it depends"
What's the difference between the vlookups?
Easiest way might just be a select case statement
select case cell1
case 1
vlookup(a1,somerange,2,false)
case 2
vlookup(a1,somerange,3,false)
case 3
vlookup(a1,somerange2,2,false)
case...