I've always heard that dolphins are pretty smart

Although exact locations on the ranking are generally disputed, according to standard assessments of problem-solving abilities, social complexity and self-awareness the most intelligent species would be: humans chimps (Pan troglodytes) bonobos (Pan paniscus) gorillas (Gorilla beringei and Gorilla gorilla) Orangutans (Pongo abelii and Pongo pygmaeus) baboons (including Papio hamadryas, P. anubis, P. cynocephalus, P.papio, and P. ursinus) gelada baboons (Theropithecus gelada) various macaques (genus Macaca, including M. arctoides, M. fascicularis, M. fuscata, and M. mulatta although it is possible others should be considered) elephants (Elephas maximus and Loxodonta africana) cetaceans: bottlenose dolphins (Tursiops truncatus), rough-toothed dolphins (Steno bredanensis), "Killer whales" (Orcinus orca), the false killer whale (Pseudorca crassidens), white-sided and dusky doplphins (several members of genus Lagenorhynchus), pilot whales (Globicephala macrorhynchus and G. melas), Risso's dolphins (Grampus griseus), Spinner's dolphins (Stenella longirostris) and possibly other members of genus Stenella, Belugas (Delphinapterus leucas) --and other cetaceans may have to be considered for such a list, including sperm whales and humpback whales. parrots: African gray parrots (Psittacus erithacus), Keas (Nestor notabilis), blue macaws (Anodorhynchus hyacinthinus), Senegal parrots (Poicephalus senegalus), Budgerigars (Melopsittacus undulatus), Scarlet macaws (Ara macao), and arguably at least a dozen other parrot species, althought the above are some with the most supporting information available. corvids (crows, ravens and jays): New Caledonian crows (Corvus moneduloides), Japanese crows (Corvus levaillanti), rooks (Corvus frugilegus), western scrub-jays (Aphelocoma californica), and possibly other members of genus Corvus octopuses (including the common octopus, Octopus vulgaris, and the white-spotted octopus, Octopus macropus, as well as potentially others) wolves and domestic dogs (Canis lupus and Canis lupus familiaris) raccoons (Procyon lotor) possibly domestic pigs (derived from Sus scrofa) arguably, rats (the black rat, Rattus rattus, and the closely-related Norway rat, R. norvegicus) You should be able to find your top 50 in those groups. Note that intelligence is not confined to mammals, or even vertebrates (octopuses are commonly thought to be equal or above dogs in general intelligence).

Me and 49 friends.

There is no definition of "intelligence" and no way to measure it.