I never get Chespin and Bulbasuar though. Just loads of charmander, froakie.
What I present here might interest you and I think it's a good discussion for this thread, and in fact matches your remark. Comment below.
Someone showed me his data for Wonder Trade. I've included minimal data that I note below. As of right now, and with me ordering based on my experience for the noted ties, the Top 10 includes:
#10 - Scatterbug. Scatterbug trading in general is popular for the many Vivillon. Sorry, no Poké Ball Vivillon included.
#9 - Bunnelby. Caught early, nothing special, just a Pickup acquisition like other generations. This tied for #8.
#8 - Ralts. A popular breeding project for new Champions and old. I actually bred for a Timid one in Gen. V for someone and ended up with a boxful, which I sent out myself. Six more in my next session!
#7 - Furfrou. Not as early (Route 5), but I guess styling is popular.
#6 - Flabébé. I must confess I send out some white and orange ones, myself. Five today, in fact. This tied for 5th.
#5 - Charmander. Another popular breeding project, especially for Egg Move experiments. I just got a Charmander with four different Egg Moves today, quite a challenge to put together. I for one bow to our Japanese Pokélords. (In case you're wondering why I say that, it's tagged JPN.)
#4 - Honedge. Do I need to explain why
Aegislash is so popular?
#3 - Eevee. Here is where I reorder the top entries using my data from today. I got an Eevee, which tied with #2 in the charted data, and I'm not surprised since Sylveon is clearly popular (or is it the other seven?). They sometimes come with Charm learned at birth for immediate Lv.2 evolution with two Hearts in Pokémon Amie. Oddly, I don't get too many, but I did get an Anticipation one once. Still have it untouched.
#2 - Fletchling. I'm tired of these guys, but they are the first early-catch bird to use Fire as a typing. I haven't seen any special breeding projects come through for them, however.
#1 - Froakie. Apparently, Protean is good for you! This didn't lead the chart, but I got two more today and was not letting this rank any lower than #1. This seems to be my most common receipt, and I have two or three Protean and some others with Egg Moves. I'll experiment later breeding-wise, but don't know if I should send the results. What I hate is getting them without Egg Moves or Protean; seriously, I don't need those.
Honorable Mentions: Pidgey and Luvdisc tied for 10th and thus get mentioned here. Pidgey is an early catch and frequently seen by me, though this depends on the time of day. I also have a couple of WT Luvdisc from Ambrette Town. I know these may be newer players trying out WT for the first time and being shocked to get a 5IV Froakie with Protean for their measly offering (and if someone's sending that, you know they're breeding for 6IV).
Comment: The data shows two Bulbasaur and one Chespin among the trades. I don't think I've seen Chespin recently (I got mine from Shauna, and think I have a second somewhere), but I have an Egg Move Bulbasaur in my PC somewhere from Wonder Trade to keep my Lv.100 Venusaur company.
Does this data generally match your list, folks? Discuss, and of course keep bringing up the cool things you get!