Baroni/Lindland was a great fight. Truth be told, the entire UFC 41 card was quite remarkable, especially Uno/Penn, and my personal favourite, Mir/Abbott, where the valuable lesson of "He who shoots his mouth off, has lost the amount of face that he would have lost if he had just kept his mouth shut, multiplied tenfold." was learned.
Of all time, and keep in mind I haven't seen many, only 1-5 and 38, 40 and 41. Sudo/Remedios.
As a wrestler, I loved Severn suplexing an undersized Anthony "Mad Dog" Macias in UFC 4. A perfect suplex is a beautiful thing.