Cleary, as has already been stated, the top sport at Hopkins is Lacrosse at all levels. The Men's team is the most storied program in the history of collegiate lacrosse and the women's team is perrenially ranked in the top 20 for Division I programs.
All other sports at Hopkins at Division III, and actually many of the teams are well-ranked in Division III. Hopkins is actually in the top 15 every year in Director's Cup standings which tracks success in DIII athletic programs across all sports.
The top teams annually are Swimming (rank in top 5 in national standings), Baseball (top 10), and Soccer (both men's and women's make the NCAA tournaments almost each year).
Full details on Hopkins Sports:
Johns Hopkins Blue Jays - The Official Athletic Site for the Johns Hopkins University