To me it is called the Napoleonic Period since the little rascal started nearly all the wars.
Well on that note I thought I would add, in reverse order, my five choices, which do include at least one battle without Wellington and four without the great man (sorry Matt)
5)
Oporto 18 May 1809 Wellington’s first battle on return to the Peninsula and fascinating combination of special ops and amphibious landing with an impressive unexpected river crossing. Drove Soult into full retreat
4)
Buçaco September 27, 1810: Classic confrontation of French column against British line in which Wellington dramatically bloodied Massena despite being outnumbered over 3-1.
3)
Waterloo. It is hard to think about the Napoleonic Wars without considering this one. An Icon.
2)
Salamanca 22 July 1812: An unintentionally initiated action resulting from the maneuvering that enabled the Duke to exploit a gap in the French position with brilliant success. It entailed dashing cavalry charges by dragoons and hussars, stubborn fire fights by both skirmishers and units in line, retreat and continued fights in all terrain. It ended with Marmont's retreat and was Wellington’s greatest victory to that point.
1)
Fuentes de Oñoro 3-4 May 1811: Perhaps one of the most thrilling and closely fought British wins it featured all the classic aspects of an epic Napoleonic contest including cavalry assaults, broken lines, resistant squares, cavalry versus cavalry clashes, brilliant rifle skirmishing, column versus line, charges and counter charges, massive bombardments, brutal hand to hand fighting over terrain as varied as open plain to village streets. It also marked an amazing rescue of a cutoff British Division by the Light Division’s perfectly executed march into the plain and back under the nose and continuous assault of massed French cavalry and supporting Infantry divisions.
Honorable mention:
Barossa (5 March 1811), a gutsy win by General Graham snatched from the jaws of a near defeat by ambush resulting in the first British capture of a French Eagle;
Corunna (16 January 1809) a stubborn British defiance in the wake of retreat marked by the death of the British commander Sir Thomas Moore which became a rallying cry for British troops later in the war and
Badajoz (6 April 1812), a bloody British storming of a seemingly impregnible fortress by sheer guts and force of will.
