What LoneKnave said--what do you want? If you're looking for a bit of combat power, Mysterious Stranger Gunslinger isn't bad (as pointed out to me by EndlessForms), and the pistol/whip combo fits with being an archaeologist. Besides, gunslingers get 4 skill ranks/level, so you won't fall as far behind in the skill monkey race as you would taking pally.
|nate lange RPG Superstar 2012 Top 32|
+1 for need more info...
what level are you? are you looking to dip something but stay mostly an archaeologist, or are you done archaeologizing and looking for a new career? what do you mostly do now? what are you hoping to gain? those are probably the most important...
if you're still really low level (like 1-2) archaeologist could be your dip and you could add a second class that will become your main... a dervish dancing magus could potentially be great in that case. if you're like 3rd or higher your magus level would be frustratingly behind, but you could dip many of the options already listed: paladin for saves/bunch of little swift heals/smite bonus to attacks/AC; oracle for fulltime Cha to AC; horizon walker for movement/utility; lore warden for feats/toughness (and an easy route to dervish dance, if you want it). if you're thinking about leveling in another 3/4BAB class you should think about leveling to a multiple of 4 in bard first (and, if dipping, possibly taking 4 levels in the dip) to minimize the impact on your BAB.