Hollandaise is one of the five mother sauces, and a great topping on eggs benedict.  But there are many well known ways to slightly change hollandaise to create a different sauce.

Bavaroise- made with crayfish butter, cream and crayfish meat, common on fish

Bearnaise- Tarragon reduction, fresh tarragon and chevril, common on grilled meat

Choron- Bearnaise with tomato added, commonly served with meat and poultry

Foyot- Bearnaise with Demi-Glace, common on Meats and Offal (oragans)

Maltaise- Hollandaise with blood oranges, (some suggest adding orange zest also) commonly paired with asparagus

Mousseline- Hollandaise with heavy cream, common on fish and asparagus

Paloise- Hollandaise with mint reduction and fresh mint, common on grilled meats

Royal- Equal parts Veloute, hollandaise and whipped heavy cream, common with poached poultry and fish.

Baisc Hollandaise Recipe:

4 egg yolks
12 oz melted butter
2 Tbsp white wine vinigar
lemon juice
salt
peppercorns

1.  Reduce white wine vinigar with cracked peppercorns, by about 3/4 the volume.  Let cool
2.  Add egg yolks to the reduction, and whish over a double broiler.  Remove from heat if mixture is gettign to warm.  When egg yolks triple in volume stop whisking.
3.  Slowly add butter, if hte sauce starts to break add a small aplash of water to it.  If the sauce gets to thick add a splash of lemon juice. 
4.  Finish the sauce to taste with salt, pepper, or cayanne.  Or make another type of sauce form it.

When making Bearnaise, Choron, or Foyot sauce add the tarragon to the vinagar before making the sauce.  Add mint to the vinagar before making Paloise.