According to polls, the EPP family is the strongest political group in 11 states, the Socialists in 6. The Liberals/Renew are ahead in 3 states, and the Euro-sceptic national conservative ECR and the ID (right wing) in 2. The Left (GUE/NGL) is leading in Ireland. In Hungary, Fidesz was in the lead (not yet part of a party family) and formally independent parties were ahead in Lithuania.
The picture is similar if we look at the strongest single party and not the largest party family: The EPP leads in 9-10 states (tie between the major EPP and S&D member parties in Portugal), the Socialists in 6-7. The ID is leading in 4 (+3). Liberals and the ECR in 2. The left is ahead in one member state. Fidesz (not yet a new party family) is ahead in Hungary. In the Netherlands, the still independent BBB was in the lead for the first time.
The lead over other party families or other individual parties is often very narrow (e.g. Slovenia, Poland, Belgium, Denmark,France, Bulgaria), or other polls see another party families or individual parties in the lead.
Read the full analysis here.