BC2: Valparaiso Rush

Valparaiso

Rush defense:  This map is growing on me, now that I know more of its small tricks, where people hide, where to intercept parachuters, where snipers like to camp.  It's also a fairly large map (5 bases) with rather diverse sub-zones, such that a team who specializes in a particular rush style (say, snipers and a tank-rush) and breezes through one area may get stonewalled at the next if they can't switch tactics or skill sets.  The overall tenor of defending the map, or the one I prefer to adopt, is anti-vehicle.  The chopper is present at most bases, and represents the biggest threat in terms of death and as a spawn point for parachuters.

Fishing Port:  The attackers get a tank and a chopper, so I almost always spawn as an engineer initially to try to tracer/RPG the chopper, which gets to the base a full minute before everything else.  I like to setup near the warehouse on the water (adjacent to the heavy MG) because the chopper usually makes its turn in the back, and that's the easiest point to tracer it.  And if that fails, you can usually hop on the MG for some light damage while it's over the water.  The remainder of the round usually involves staying engineer for constant anti-tank anti-chopper work, but during lulls I'll switch to assault with the AN-94 and a 4x scope to take out rushers from a relatively safe distance towards the back of the base.

Lighthouse:  I'm all about the stationary AT on the roof, here.  Attackers still get one tank and one chopper, and if you can't tracer the chopper you can use the AT to spam it with missiles until you get lucky.  Also, the AT has a sight line to a forested area where enemy infantry likes to setup when pushing, so you can spot AND missile them while still (relatively) safe towards the back of the base.  I typically engineer full time on this map so I can tracer when the chopper is behind the AT's aiming arc, and jump down to RPG a tank if it makes it past the front line.  The only exposure at the AT is if someone gets a sniper into the lighthouse, at which point you pretty much have to give up on half your base anyway.

Village:  There are enough buildings, docks, nooks, and crannies here that recon makes the most sense.  VSS is probably the way to go, since you can still hip-fire if necessary, and the built-in scope lets you do long-range spotting and sniping on guys coming down the hill.  I like to park on the shore, in one of the buildings between the hill and bravo, and spam motion sensors while keeping an eye out the window to the opposite side (towards alpha, which is generally the first infantry target).

Hilltop:  The area of engagement here is rather small, so I like to go assault with XM8 and rely on natural vision to spot targets atop the hills.  It's suicide to go up there as a recon, and standing in the back of the base to snipe means your motion balls are worthless AND you can't see anything anyway.  I'll typically park near alpha around a concrete block and just shoot whatever moves.  There's not much strategy here.

Last stand:  The stationary AT in the back of the base points directly down the main road, where the enemy tank will likely park to provide long-distance covering fire.  Thus, I park on the AT and kill every vehicle that dares brave the road.  There's some risk of exposure to snipers, but it's mitigated if your team is aggressive with pushing the line forward.  If it's just you vs. whoever is on the road, you can missile-spam them the whole game.  Kit is almost irrelevant for this strategy, but I tend to medic here to heal myself when necessary, and if the AT is destroyed I can still long-range guys down the road (or in the river if I head to the side of the base) with the MG36.  If the line of engagement crosses the river, you've already lost, so there's little sense in planning for CQC.

Rush attack:  Full medic the whole map.  The MG36 is perfect for sniping and covering fire, but you can still rush behind your infantry and keep them alive when you want to be more aggressive.  I've found a few useful nests:

Fishing port:  There's a hill that splits the final wooded approach into two roads.  Atop that hill, within deep tree camo, is a small depression you can duck into and still fire out of, in the shade, totally protected.  It offers unobstructed view of the foreward-most heavy MG, the building next to it, and the alpha M-COM.  I wait for my team to set the M-COM and then kill anything that tries to come close.  Once that's done, I jump down the western slope and stand behind my infantry as they press bravo, keeping an eye on the tower by the treeline (enemy spawn point).

Lighthouse:  Stay behind your team and just heal/rez people as they climb the hill.  Once you're on top, there's a concrete block wall on the eastern side that you can duck behind for full cover, but aiming around to the left lets you cover M-COM alpha and the main base, and the right lets you pick off anybody trying to flank your squar.

Village:  Sneak down the western hillside, up against the rock cliff, to pick off forward infantry while your team advances down the main hill.  Once your team's fully inside the base, there's a building on the water where you can sneak up under the floor but still shoot towards their spawnpoints towards the back of the base (and M-COM bravo).

Hilltop:  The magic spot here is on the back of the hill between the two road forks.  It might take some work getting up there safely (it's a popular defensive position) but once you're up there, crawl to the southern end and get behind a tree.  You have total sight to alpha (including the floor gap underneath, which is important here) and you can spot and occasionally snipe dudes spawning in the back and running to the building surrounding bravo (though you don't have direct sight unless someone destroys every building on that side of the base).

Last Stand:  The ridge of rocks and shrubbery lining the main road gives you a little cover, and you can shoot the two guard towers from there (and the stationary AT if you're lucky).  Once your team's inside the base, I like to drop down into the river and cross on the eastern path, sneaking up the hill and laying down covering fire from next to the cliff, since you can cover bravo and the back-spawns from that position.  Just try not to get shot too much since you're rather exposed there.