There are a lot of things to like about Padua.  It is easy to get to from either Venice, Milan, or Florence by train.  It's really not too bad to get to from Rome either.   Once arriving in Padua, it's a short 10 euro taxi ride to get to just about any hotel.  I like the Hotel Belludi 37.  An alternative is Albergo Verdi and despite the small bathrooms, Hotel M17 is a good value.

Padua is compact and very walkable.  I enjoy walking around one of the four squares and visiting the various markets.  The produce market is the most colorful and enjoyable in Italy.  I'll stop in for a cafe at the grand Cafe Pedrocchi, visit the Duomo, and walk through the charming Jewish Ghetto.

Other sites to see on a visit to Padua are:

Scrovegni Chapel: The superstar of Padua.  Giotti's frescoes, in my opinion, are more amazing than the Sistine Chapel.  Worth the trip to Padua alone.

The Churches:  The most famous is "Il Santo" or Basilica di Sant'Antonio da Padova.  Pilgrims come in awe to touch the resting place of Saint Anthony and pray in this marbled church.

Cafe Pedrocchi:  This neoclassical style is rich in marble, open ceilings, and the perfect place to sit to watch the world go by.

Palazzo Ragione:  Outside of the vegetable market, the largest roof in all of Europe.  The massive inside space adorned with frescoes is a work of art.

There are also examples of architecture, good art museums, and botanical gardens to spend time at.  Compared to the big tourist cities of Italy, Padua is much more laid back (and less expensive) and is a terrific trip for your 2nd or 3rd time to Italy.