My top 5 based on ones encountered(I've seen dozens more of some of these, like they actually spawned but I didn't encounter them.
1. Pidgey Caught 34, Seen 43 (Really seen 60+)
2. Eevee Caught 31, Seen 39 (Really seen 44 or 45)
3. Weedle Caught 27, Seen 36 (Really seen 60+)
4. Caterpie Caught 19, Seen 23
5. Spearow Caught 18, Seen 20
Rattata's not on this list as I've only encountered it 25 times and caught it 16 times, but it's safe to say I've probably really seen it spawn at least 70+ times, Drowzee is also up there with maybe 50+ times spawned, sometimes my nearby map will have 5 Drowzee and 2 Hypno at the same time.. Other Pokemon like Zubat and Magikarp that are common for other people are scarce here. I've seen 10 Zubat's and 8 Magikarp. Caught about half as Zubat waste's poke balls and Magikarp always breaks out and uses it's Run Away ability... With the exception of Eevee I tend to only encounter Pokémon who I still need to evolve for my Pokedex.
One time I went to two pokestops near a lake with lures going on both 24/7, it was like a flower petal shower and as soon as I got there a Pidgey spawned, in my head I said "I don't need you Pidgey, in any sense of the word, shoo", then Rattata spawned next to it and I said "I can't wait to catch a new water Pokémon like Goldeen or a Poliwag?", immediately after that Weedle spawned and I said "Oh good, the gangs all here."