Take for example the words 'I' and 'you' (or 'I' and 'we'). Is it more reasonable to analyze them as different lexemes, or as different forms of a same lexeme inflected for grammatical person (or number)?
As pointed out in the comments, it doesn't make much sense to ask what's the right view, but what are the advantages and disadvantages of these opposing views? Is any of them more widely adopted in a given context?
I believe the commonest view is that words like 'I' and 'me' are just different forms of a single lexeme, inflected for grammatical case. But are 'I' and 'you' (or 'I' and 'we') different lexemes or again just different forms of a same lexeme, inflected for grammatical person (or number)?
Insights for languages other than English would also be very welcome.