Some ideas:

Ochakov 1497 - Poland vs. Tatars
Orsha 1514 - Poland vs. Russia
Mohacz 1526 - Hungary vs. Turkey
Obertyn 1531 - Poland vs. Wallachia (Turkish vasal state)
Starodub 1535 - Poland vs. Russia
Danzig 1577 - Poland vs. Danzig (any german faction will do)
Wielkie Luki 1580 - Poland vs. Russia
Pskov 1581 - Poland vs. Russia
Byczyna 1588 - Poland vs. HRE
Revel 1602 - Poland vs. Sweden
Kirkholm 1605 - Poland vs. Sweden
Klushyn 1610 - Poland vs. Russia
Moscow 1610 - Poland vs. Russia
Cecora 1620 - Poland vs. Turkey
Chocim 1621 - Poland vs. Turkey
Smolensk 1634 - Poland vs. Russia
Ochmatov 1644 - Poland vs. Tatars
Zolte Wody 1648 - Poland vs. Zaporozhyan Cossacks
Korsun 1648 - Poland vs. Zaporozhyan Cossacks
Beresteczko 1651 - Poland vs. Zaporozhyan Cossacks
Czestochowa 1655 - Poland vs. Sweden
Podhajce 1667 - Poland vs.
Kamieniec Podolski 1672 - Poland vs. Turkey
Chocim 1673 - Poland vs. Turkey
Vienna 1683 - Poland + HRE vs. Turkey

I know its probably way too many, but its sth to choose from.

Regards
EC