The french league is refreshing in my opinion. Hardly any restrictions to foreign players or max stables, and the league itself is quite open as in who can win it.
Really enjoying my current Monaco save.
French and Italian leagues are very fun. I also had a blast in the Russian league in fm11, challenging because you need 5 russian national players on the field at all times
Start somewhere random (I went to Red Star in Serbia), play 2 seasons and win stuff. Win the ACON with one of the strong but low rep african sides (Mali, Morocco etc) - then have your pick of Medium-High rep teams (i got Dortmund after winning ACON with Morroco) from there I won everything 1st season, So I resigned and now im looking for a decent Ligue 1 team to play with.
I've found this travelling around to be a great bit of fun. Nothing dull because you have to reassess your new club/nation etc
I have 2 saves on the go, one with Southport and one with Shakhtar, both challenging teams. When I have had enought of one save for one day I just flick onto my other one. I found the Cypriot interesting too with APEOL Nicosia.